I've been a Linux user for 20 years, and Linux-primary for about 15 years. That puts me in the minority in most groups, even among developers who these days are still mostly Mac-o-philes if they're non-Windows. For that entire time, it's been a running gag that "this will be the year of the Linux desktop." And, of course, it never is. Whatever that means.
Guess what, we're now in the age of Linux. On the desktop. But it's not what you thought, and probably not what you wanted.
According to Ars Technica, the second most popular desktop OS after Windows is no longer Mac. It's... Chrome OS. Chromebooks run Linux, but are probably not what most people meant by "Linux on the desktop." They're also four of the top ten selling Laptops on Amazon. (Two others are Mac.)
Meanwhile, almost every Windows machine being sold today supports "Windows Subsystem for Linux." It's a Linux installation built by Microsoft on top of Windows, that integrates into Windows. You can even put a common Linux distribution on top of it. For the moment they don't support GUI applications, but that's being actively worked on.
I am not the first to predict that Windows, over the next several years, will mutate into a sort of Linux distribution with a thick, proprietary Windows layer on top of it. Or at least, the way many people use it will look like that.
And of course there's also Android, the world's most popular smartphone OS, which runs Linux under the hood.
This should all be good news, right? Linux is winning on the desktop just as it won on the server. At the current trajectory, it's only a matter of time before Linux is running on a majority of desktop/laptop computers. So it's finally the year of the Linux desktop, right? Why is no one cheering?
Say what you actually means
The reason this is not unqualified good news is that all of these developments are about Linux the kernel. They're not about Linux the ecosystem. Or, more to the point, they're not about GNU/Linux. "Linux on the desktop" never meant the project managed by Linus Torvalds running everywhere. When most people in the last 25 years talked about "Linux on the desktop," what they actually meant was the GNU/Linux ecosystem. The KDE or Gnome desktop. Free Software taking over the desktop, not just a particular application that 99.9% of the population doesn't care about.
What we really wanted, but never said, was a Free ecosystem, one optimized for user-autonomy and privacy, one built by a community rather than a central corporation, one that we could influence as users to avoid dark patterns designed to keep you within the walled garden.
What we got is a Linux kernel-based walled garden. Actually several: Chrome OS, Android, etc.
Centralized walled gardens have an advantage that Free Software can't have: Direction and Consistency. It turns out, most users don't give a damn about their own freedom, their own privacy, or their own sovereignty when it comes to software. That shouldn't be a surprise, though. They don't care about it in any commercial endeavor. That's how and why large corporations in unregulated or under-regulated markets are able to violate their users with impunity (selling their data, dark patterns, price fixing, etc.). Most users simply don't care, or simply don't understand. And that's fair; most of these topics are complicated, and it's non-obvious what you're agreeing to when you do business with a random company even if you did care. Transparency is great, and we need more of it, but that's not enough. Slickness and ease of you use trump everything, including long-term self-interest.
If what we want is really a Free desktop... we need to say that. Don't use euphemisms. Don't use a particular application. And for god's sake don't talk about Open Source. Open Source doesn't care about user freedom or rights; it cares about code quality and cost effectiveness, and if exploiting free labor without compensation saves money, Open Source will do it. This shouldn't be news to anyone that has worked in Open Source for any length of time. Free Software is, and always has been, political. (And if you're using a permissive license, you're encouraging Open Source, not Free Software, and you are doing nothing to aid user freedom.)
We need to change the structure of the game, because the current structure of the game is stacked against the user, against freedom, and against personal sovereignty. Yes, that may include government regulation. Techno-libertarians, tough shit. The free market is not Free and never was. That was always a pipe dream.
Besides, the battle for the desktop was lost long ago. The battle for the server, and the data, is the the current fight. And we're losing those, too.
So yes, the Era of the Linux desktop is here. The era of the Free desktop is not, and may never be. If we want an era of Free computing to ever come, we need to change strategy.