Their cut is mathematically fair but the inputs for this formula are mostly pain tolerance levels of consumers and producers. I meant fair for having a monopoly. Either you’re a utility or need to be broken up so that actual competition can take place.
Steam Deck and Proton killed Linux gaming because nobody bothers to do native ports. While I don’t agree with that approach it kinda works but it’s not that Valve does this because they like Linux. They’re scared of losing their monopoly in case Windows changes too much.
There are ARM native games on Mac (Disco Elysium for example) and Steam has no issues with them. Not having ARM client though means that you’re running a dynamically recompiling web browser through a translation layer resulting in terrible performance.