Valve already tried this and failed. The reason it failed is because there wasn't a single reason for people to switch to Linux for gaming.
Steam Machines failed because ValvE mistakenly, assumed that developers would port their games to Linux.
SteamOS ran Debian.
Then they worked on Proton, which is a translation layer so developers dont need to port to Linux, just make sure their Windows games are compatible with Proton.
Then the SteamDeck came with SteamOS 3, based on Arch and running Proton on top.
The rest is history as they say.
Check ProtonDB to see how compatible your favorite game is with Linux+Proton.
There is no SteamOS 3 for general public, just for the SteamDeck.
There are distros that tries to cover this, HoloISO, ChimeraOS and Bazzite.
The rumor for the delay for an official SteamOS is Ngreedia hate for open spurce drivers. They only release closed binary blobs, which Linux distros needs to enable separately because of the GPL.
So given that 80+% of gaming PCs are infected with Ngreedia s hardware, Valve has been hesitant to release their version, since everyone will not dare pointing fingers at Ngreedia and instead will blame Valve when they cant run SteamOS.
AMD doesn’t have that “problem “ because they embraced open source openly and the needed drivers are already part of the Linux kernel.
What changed? I don’t know.
Maybe Ngreedia is releasing full open source drivers and told Valve or maybe Valve grew a pair, told Dear Leader Jensen to kick sand and will place big warnings all over that only AMD and intel gpus are compatible.
Either way, this is exciting.