Bazzite fills a SteamOS-sized hole with a decent level of hardware support. Unclear how long that'll be the case - I don't see it surviving the release of a GA SteamOS.
It's snapshotted from Arch, once a year they bump the kernel and include "updated Arch Linux base" as a release note.
SteamOS 3.7 is still on Kernel 6.11 and KDE Plasma 6.2, for example. Bazzite is 6.17 and Plasma 6.5.
This matters if you're using more recent hardware or want the latest driver optimizations. My 9070 XT is supported by Bazzite, SteamOS won't even boot.
Especially on the Beta branch, I'm getting several system updates per week. I check for one every time I wake it up, along with checking for any available game update downloads. Originally moved to the Beta branch to get the new 8BitDo controller features (Mid-July maybe), but it's worked well enough I've never gone back to Stable.
i'm still not sure why anyone wants a GA steamos, the value is in the vertical integration, no? the "console experience" are mostly the bigscreen mode and other things already available in things like bazzite, while being a more general distro...