Other companies do the exact same though, Nintendo controllers don’t support non-Nintendo devices (although they’ve been reverse-engineered for Steam and Linux).

You don’t have to play every game through Steam, switch to the controller action set in desktop mode and and it’ll work as a basic controller for any game.

All of the Steam Controller’s actually distinguishing features wouldn’t work with XInput though. If you’re not interested in that stuff you’d save money going for a basic Xbox controller or third party one.

I imagine it’s like the Deck where desktop mode has 2 modes so you can switch to use it for non-Steam games.

the number of windows pc users has been plummeting lately, and it’s not in favour of linux but mobile os’es

Non-gaming PC/Windows users are going down, but PC gamers are at all time highs and still growing.

Ultimately the EGS has shown 12% is not profitable, a lower cut would be nice for smaller devs but I don’t see why Valve would when every other platform of Steam’s size also takes 30%.