You'll look back in 20 years and remember this as the final few years we used linux on personal devices.
For me it was always one way to have UNIX at home, that is all.
In fact, Solaris, Irix and NeXTSTEP have always been my favourite UNIX clones.
As long I can plug into some flavour of POSIX, I am good, as do most folks in big corps.
But that doesn't mean Linux or OSS is going away anytime soon. There's more Linux systems in the world than every other OS that's ever existed combined. For a large portion of the world a Linux (Android) device is the only computing device they've ever used. Even in developed countries, desktops are less and less relevant and mobile devices are #1, and outside a few select countries, that means Linux (Android).
And Linux is gaining steam if anything thanks to AI, since most of the infrastructure related to producing LLMs runs only on Linux. No one's running Windows server on a 300k node cluster.
And to address your point directly, installing Linux on non-Linux hardware is still better than it's ever been. More hardware is compatible than ever before (I've been running Linux since the early 2000's) and while running non-Android Linux on phones isn't great, even that is better than it used to be.
But yeah, we probably won't ever reach the "whole stack is open top to bottom" future that people like RMS dreamt about...
We will because that is the only sustainable mode of operation in the long term. Every proprietary stack goes through ups and downs, and is eventually displaced. You must be open to persevere.
It's just a matter of time.