For better and worse everything productive is becoming OS agnostic. In 15 years I don't think many first-class applications will be truly native. They will be UI via HTML (webapps, electron, etc), CLIs based on POSIX, or company maintained UI frameworks which break OS styling conventions (JetBrains, etc).
OS agnosticism isn't just webapps taking over. Docker is making development from the ground up be OS agnostic.
I see this in my personal life as well. Every day I use MacOS, Linux, and Windows -- OS doesn't really matter much anymore to me.
The weird revelation to me was that the goal of what a decent OS is keeps moving, even as what we want to do doesn't change much in nature.
20 years ago I was on FreeBSD and it was fine. But as laptops became mainstream, and even the main linux distros were completely impractical.
Now we have really good linux laptops, but tablet form computers are maturing and we're starting to see very good ones, and linux support is still generations behind (heck, windows support is still meh)
I'd expect linux to be viable there in 4 or 5 years, when the dust settles, but then will the compatibility extend to the machines on the better form factors of that time ?
Basically "the year of linux on the desktop" meme has stopped being about sheer viability and more about what you're willing to give up to keep using linux. As long as it doesn't become the primary target of the more innovative hardware makers out there, I wouldn't expect to solve this situation anytime soon.
there is no reason to keep using a walled, closed desktop OS in the 2020s