When considering the future of tech, there are three factors to have in mind. (1) Today, the tech sphere is dominated by the phone. It is the core element of the digital experience. However, this doesn't mean other tech doesn't have a role - tablets, computers (PCs+laptops), television, whatever-a-Roku-is, these all play roles in our lives. (2) Within the digital sphere, our plurality of devices makes cloud services that much more enticing. When Google provides cloud services, then using Google services altogether becomes that much more integrated. Furthermore, social media is a big part of our phone use, like it or not. Following data integration (cloud, camera, etc.), social media, we have maps and navigation. Finally, (3) tech and 'fashion' are a factor. It doesn't hurt Apple that their stuff is, well, fashionable.
Saying mobile is a big deal isn't a hot-take, but worth diving into. In this climate, we can see why Apple and Google are included in FAANG, and Microsoft isn't. Microsoft mobile sucks and is dead, and Microsoft software generally sucks and the UI looks and feels like a Soviet committee designed the UI and Brezhnev's corpse rubber stamped it; that is to say, ugly and terrible. Seriously, this company is the eighth wonder in the world, the wonder being they haven't gone out of business. Going into the 2020s, I feel like, as the role of the computer/laptop diminishes, Microsoft will slowly die (or become permanently enmeshed as part of the military industrial complex, which wouldn't surprise me, as it seems like that's the only thing that's working out for them), surviving as a zombie based on the goodwill of OEM laptop producers and its diminishing monopoly perch on Steam. Public service announcement: If you aren't a gamer, and don't use Adobe whatever religiously, and need a laptop - get one with Ubuntu on it (like through Lenovo), or buy one from System76 or Purism. Windows is pointless and terrible.
I predict the computer/laptop will diminish in prominence. This is (A) partly maintaining the trend, but also (B) because of convergence. Convergence means that one device can act as mobile and desktop. If you've ever used a Raspberry Pi (an ARM device the size of a fat wallet), you can see what I mean. Or even the Macbook M1 - that's a desktop running on a phone chip. Today convergence looks like hooking your phone up to a screen, and having a desktop experience at the desk, and unplugging and having a mobile experience on the go. For most consumers, this is clearly a powerful sell. Suppose you're a normal person (you have a smartphone) - if you bought a 32" monitor for around $150-$400, you saved a whole boatload NOT buying a smart TV. Now you can hook your phone up to the TV, using your phone like a Roku (basically), and stream whatever. You can Netflix and chill! But you can also use it like a Desktop. Now you don't need to buy a smart TV or a laptop, cause your phone + monitor does the whole job. Congrats, you probably saved around $600-$1300.
Mopping up with all of this, two companies today look most prominent to me (assuming no Linux chad company comes in and disrupts). Google is in a good position, because Android Desktop is a thing, and because Android has huge market share, and nearly anyone would be fine using one. The other is Apple - they have the capacity to do this, although they are much more oriented towards having many different gadgets, rather than converging them into one. So they have the capital to do it, but it's unclear if it matches with their design, engineering and marketing philosophy. Meanwhile, Microsoft will do nothing gamechanging, only playing constant catch-up at best, perhaps making a decent product here and there.
The next consideration is the digital sphere. In some obvious respects, this is where Linux really lacks right now. On mobile, well, there isn't really a mobile Linux yet, so there hasn't been those apps (Instagram, Facebook, Twitter, Tinder, etc.). I guess it's not impossible, but it would probably need a larger market share than zero to compell developers to make apps for it. But there's more here than you might think.
Privacy advocates today will lament that 'no one cares about privacy'. The problem here is the layperson can't care about privacy, and even specialists can't always go 'all the way'. See if you use an iPhone/Android phone, you already know you're had at square one. Mobile service and GPS can be used to track us down, and Google+Apple don't do much to help (lol). Communication is concentrated in FAANG+ - Gmail, Facebook Messenger, iMessage, WhatsApp, Twitter, Slack, Discord (Microsoft now!), Zoom, Teams (garbage). So we can tell people 'don't use social media', but uhh, good luck talking to people without looking like a unabomber primitivist. And Chrome dominates the search-engine landscape. Using something that isn't Chrome is actually very easy, but it's still a fact of life. And even if you don't use Chrome, you still have to worry about browser fingerprinting! Good OpSec demands using like three browsers, and being careful to do particular activities only in one browser. Normal people won't deal with this.
My point being, caring about privacy seems so hopeless, most people wouldn't even bother. I'm willing to bet the most normie person would care about privacy... if that didn't require loads of research and constant vigilance. Privacy is marketable if it's feasible. This is where Linux phones come in - there's a lot more there that supports privacy and security. You got the inherent benefits of an open-source OS, along with those physical killswitches! And more! This is something Linux-centered companies can actually traffic in that other companies (Google and Apple) can't.
Using social media will always entail a security breach, minimizing privacy weaknesses is better than not doing anything. On the other charges, a Linux phone will probably fare better - although there are inherent issues it can't quite get over (like geofencing)... except utilizing those physical killswitches!
Furthermore, the current digital sphere largely thrives on having lots of different gadgets. See, as Apple airdropping shows, using the cloud isn't primarily helpful as a sharing utility. The cloud is primarily helpful for having access to all of your stuff from any device, cause you have so many devices you use. A picture on your iPhone, a pdf on your macbook - boom, iCloud. A picture on your Android, a pdf on your non-macbook - boom, Google Drive. Now idk much about Apple's emporium of fun, but the Google Office Suite thrives off of having everything all together. And THEN it is useful for sharing. Suddenly, Google has a lot of utility, but this largely depends (but not only) on having many different devices.
Finally, we have trends and fashion - I'm weaker here. Linux doesn't have much firepower, but as a new sheriff in town, its powder is still dry. On the other hand, Google has a bit of a problem - among teenagers, Apple holds an extraordinary 84% preference, and growing. Google has a serious 'birth rate' issue then.
All together, I feel like the trajectory will play something like this: Microsoft will survive longer-than-it-deserves on pure inertia and name recognition (and Pentagon subsidies). People associate Windows with a (barely) usable computer. And institutions, at their own risk, use Microsoft tools (Outlook/Exchange, Teams, etc.) - a lot of this can't hurt Microsoft (although maybe it'll backfire, cause it's so ugly). My guess is that Microsoft will keep the computer market viable. And unless either Apple and Google feels like taking a revolutionary step, they'll continue down the path of multiple devices (Android phone + Chromebook + other stuff, iPhone+iPad+Macbook). They'll work on convergence - these are huge companies - but it won't be their main focus. At very least, in marketing. Selling a Pixel and a chromebook gets Google more money (and Google Drive dependence) than just selling a Pixel.
Basically, Microsoft is a dying whale (that might never die) that is misleading the whole industry, so Linux convergence has some time (although convergence becoming a huge deal will almost be a death sentence for Microsoft, so it's a dicey situation). Gaming is the thing most obviously keeping it alive, along with old IT departments. But things change, and GPUs are impossible to buy right now - PC gaming might stagger? That's getting speculative though.
Then, all else being equal, as the desktop/laptop dwindles in importance, I imagine that convergence will become more and more important. For most people, they can get the computing power they need out of their phone, and if it can act as a desktop, they can save themselves hundreds to thousands of dollars using their phone instead of a laptop/desktop. Google will probably bite the bullet first, but as I indicated above, it's not the sexiest with the kids. Apple is very invested in its whole gadget ecosystem, so I'm predicting they'll be more reluctant on convergence. Who knows though.
This gives Linux-centered companies a lot of breathing room to push into convergence, and it's already happening, especially as most Linux-centered companies have forgone dominating the computer space, pursuing instead its niche consumer base. But, for Linux, the phones are the wild west - and convergence could destabilize (will destabilize - I'm guessing, Linux or not) the whole market. Purism, with PureOS, is a great example. The problem is lack of key social media apps right now... but again, this is still the very beginning. And there are some third-party apps as a stop-gap for now. In fact, the mobile 'battlefield' gives Linux a huge advantage. The two things that, I believe, truly hamper Linux desktop adoption - lack of Adobe stuff and lack of full gaming capacity - are not issues on desktop. Neither Android nor iOS are competing to have Adobe X and Y or Steam. The potential is very ripe here.
A strong Linux convergent device could make waves. Right now a Linux phone can give a legitimate desktop experience, making the functionality of a Linux phone highly extensible (phone to tablet, phone to laptop, phone to TV) and highly modular (want a better computer monitor? Just buy a new one (rather than a whole new laptop).) - kinda like a PC, but in your pocket - and ideally, the actual hardware of the phone would be modifiable, but maybe that's a reach. It could break us from the prison of clouds, software-as-service, closed-source software, and spyware. And as long as the thing isn't ugly, as long as it looks good, it could be a real thing.
Taking on the colossi of Google and Apple would require an army - in terms of hardware, this is a bit more bottlenecked, but in some respects, it's not entirely. Not every Linux is super-easy-compatible with other Linux's, but the world is more wide open. And because Linux is built to run on ANY device, all hardware development of (open) Linux devices feeds into the collective ecosystem. This is the bazaar, and it can spill into the hardware world. Purism alone can't take on the giants, but a bazaar of Linux-centered hardware manufacturers stand a better chance. More importantly, we limit the scope of devices inherently by pursuing a convergent device - this means the integration stuff is less of a roadblock, because we detour around it. You can catch up with the market, if you just do something else.
Plus, it's not just these enterprises at the front. Linux has an enormous community of developers and contributors. Unlike say LG, or even Samsung or Microsoft, Linux already has the raw material to make the holy convergent grail. It has all of the software engineers, it has the hardware enthusiasts. While it won't be super-tight integration, it will be better than Android + Windows. I bet a PineWatch plus a Purism phone wouldn't be that bad. Linux can forge a middle ground between Apple (totally closed, coherent ecosystem) and the rest of the world (still closed, but all sorts of different things going on) by leveraging the inherent capacities of Linux and the committed developers that contribute to it.