They tried this many years ago with the original steam machines, it went horribly. Also, you can install SteamOS or Bazite on most machines. Not sure what the issue is here.
SteamOS does not currently really work on modern desktops/laptops. You can force it but it’s really not made for it. They’re pretty clear about that, I think they even pulled down the OS download page from their site and now clearly mark it as for restoring old machines.
Likely to change soon though with the steam machine release
Yeah I’ve been using it as a daily driver, no windows partition or anything, for over a year. It’s been great. Having an AMD CPU/GPU combination definitely helps though
