To be honest you can get any decent Linux distro working for games; I run OpenSuSE Tumbleweed with an Nvidia 3070 and it works great. Steam works great, and as desktop it runs perfectly.
I also have a miniPC in my living room that I got after loving my SteamDeck being docked but a bit frustrated by switching between Desktop and the gyroscope modes. I have Nobara running on that, with Steam in big picture mode when I use it, but plenty of other things set up on there too and again it works great. I like to game but also watch twitch or browse the net on it, plus run GOG games via Lutris, and SteamOS isn’t really meant for all that even with desktop mode (as it’s not default)
So while it’s great that SteamOS is coming, I think it’s redundant in the desktop space and probably not their prime target. Getting it onto as many handheld PCs as possible is a very good idea and will give Windows a run for its money (Windows + custom interfaces from other handheld manufacturers are all a bit shit right now).
I don’t see SteamOS as it stands as a good design for a living room PC or gaming rig; but that’s not it’s target and I think it’s not realistic for people for expect it to be good for that. There is a huge range of hardware to support, while Valve targetting it’s own hardware + partners + main competitors in the handheld PC space is manageable.
Why does it matter? All that matters is that plenty of people do use Linux - literally millions of people. There is a healthy vibrant ecosystem of distros, and devs working on Linux.
I don’t care if people aren’t interested in Linux. I’m much more interested in ensuring those people who choose Linux are happy because that is good for all.of us.
And the best thing anyone can do is donate to the projects they care about. That helps projects fund development and support. It’s much more useful than trying to convince people to try Linux when they have no real interest in it.