Valve is one of the few companies that I would believe could actually be doing this for the betterment of everyone and not to just Microsoft a competitor to death.
ever since steam machines, valve has been investing more and more into the Linux desktop. They can see the writing on the wall for its Storefront if they don't make Linux a viable alternative.
Microsoft is going hard into locking down the OS against alternative storefronts such as Steam. If you buy any budget windows laptop in 2024 it'll be loaded with Windows in "S" mode which blocks installing anything outside of the Microsoft app store unless you manually fiddle with the settings; it's marketed as a "safety" feature but it's really just a way to force people into their ecosystem.
If valve wants to keep making big bucks from its videogame storefront (at least until antitrust lawsuits build ground) they need to have Linux ready to take up the slack.
does this mean one day I'll be able to pacman upgrade without ducking with my keystore
I mean maybe? Valve are pretty big on immutability and atomic upgrades which should make the package update process easier. hopefully arch is able to move towards immutability too.
