A while back, I made a post asking the subreddit if they think Linux will grow this decade and if so, by how much. It was divisive at the very least. I've seen many say that it won't or it will stay the same, and I've also seen many say that Linux will grow or hope to grow this decade. I thought it's time for me to give my opinion as a whole.
The tldr: I feel that this decade holds a lot in share for Linux as a whole.
What I think would be the big thing for Linux this decade is compatibility. Specifically, advancements in WINE, the Kernel, Proton(for the gamers, will be talking about y'all definitely), and the creation and advancement of Darling(WINE but for running MacOS programs instead).
First, recently, we got Kernel 5.11. It was supposed to help out with certain normal compat issues with AMD CPUs and some others but another thing was that now POSIX calls from Win applications running in WINE that were being sent straight to the Linux kernel are now being redirected towards WINE which should help with getting more Windows programs to work with WINE aswell as helping gamers get a better time out of Linux. If more stuff comes out in both WINE and the kernel, then the compatibility between Windows programs will increase and I suspect that this will happen even more this decade.
Second, with the creation of Proton last decade, gaming has gotten far easier on Linux and far less of a hastle. Your remaining issues now are primarily anticheat related which with steam being the developer of Proton, I expect steam games being run through Proton throughout this decade will have less issues with anticheat and less issues. Not to forget OpenGL which if you aren't using Nvidia on windows, good luck with any good performance with OpenGL, compared to Linux which has good OpenGL performance no matter what. Add all that in and I see gaming through out this decade on Linux becoming far less of a hastle and even maybe by the end of the decade, a better option than gaming on Windows(especially for non-Nvidia users).
Finally, with Darling and with its advancements, I see compatibility on Linux becoming even far less of a worry. If the Windows installer exe for Adobe Creative Cloud or HitFilm express has issues or they won't start after installation, then maybe download and install the Mac version though Darling. Darling when it advances enough will be an absolute blessing later this decade.
Now, growth. Linux as a whole(anything that uses the Kernel so your usual GNU/Linux distro and the other Linux distros that the community likes to fight over rather if they are distros or not like the two Google made such as Android and ChromeOS/Chromium OS), counting all computers(ALL TYPES, not just desktops), you could argue that the Linux kernel is the most widely used in the world. Though, here, I'm talking about usage of your normal GNU/Linux distros on both Desktop and now even Smartphones(yeah, the Pinephone). There are multiple outlets for growth this decade and I'd say we got 3 primary ones to look at.
First, Gaming and Compatibility. Like I mentioned above, gaming and compatibility will improve heavily throughout this decade on Linux as it had last decade. This I believe will contribute to some growth on Linux though not by a lot as the final reason I'll discuss a little. In games that are ported to Linux and even a lot of games that aren't but can be run through wine or Proton, they either work normally or even faster. Minecraft is an example and it runs really well on Linux compared to windows for AMD and Intel GPU users. Can't be forgetting other examples. I see performance being a driving factor though certain gaming hardware more than likely are going to have issues as of the lack of drivers.
Second, Security. With compatibility increasing by a lot, I feel many more may move to Linux this decade because of the combination of Compatibility and Security because who wouldn't if they just heard of Linux in 2025 or 2030 and they heard that security was awesome over here and they could run all their usual Windows or MacOS programs on Linux with Wine, Proton, and Darling. But that overall depends on how the word gets out and the popularity of Linux and Pro-FOSS Influencers.
Finally, I feel as of some of the recent events and many recent things done by the tech giants could cause Linux to grow and possibly Proprietary software to even decline a bit. I'm going to be honest here, a group of people that some of yall may dislike are probably going to be contributing to Linux's growth throughout this decade. I'm sure many of y'all can infer to who I'm talking about but I'm not going to make any full on mentions as I still don't want the comment section to become a charcoal grill in of itself. Though, if what is going on with big tech is enough to pose any alarm to anyone(not spying but alagations of censorship), I wouldn't be surprised if many people in the above mentioned group leave Windows and MacOS or at the very least, many proprietary programs for FOSS/GNU equivalents. No matter if you like it or not, if you agree with them or not, they could potentially cause us to grow by a lot this decade. Tbh though, I don't know what a mass exodus of that group would do to Linux on the outside.
At the end of the day, I feel this decade is when Linux will grow and improve heavily. Linux is getting more and more comfortable by the year and even now, Linux is comfortable for many.