The difference is that these 3 companies already have a market, Apple doesn't even bother trying to convince people to get games on the platform, other than iOS. I don't think they care about gaming on macs at all.
It allows them avoid being compared to PC's . They don't have worry about someone saying the Mac sucks for playing game X... because nobody will even try.
It bolsters their image that they're not just another PC.
I've been deeply coupled to Apple since 2005 and it's safe to say they've made stabbing attempts at getting serious about this a dozen times, real serious ones too, but inevitably it doesn't matter.
The most recent one that comes to mind is Mac x VR marketing push...4 years back? Ended it complete tears, SteamVR isn't even available for Mac anymore. And it was depressingly obvious at the time there was no reason for it to work out, it was clear ARM Macs were coming very soon.
The fact that they view a stabbing attempt as a step toward being serious seems like a big part of the issue. In order to have a successful platform, you need to be dedicated to the idea of being a platform and continue pouring in the resources whether it feels like it's aligned with this quarter's business themes or not.
Making games is already difficult, nobody wants to do extra mile to support a platform, Valve made the right choice with proton, unfortunately, that means less incentives to have a native gaming experience on Linux.. I'd say the tradeoff is worth it
Apple should do something similar, but they'll never do since their users expect quality over anything else, wich is why they market Game Porting Toolkit as a testing platform, as opposed to a shipping platform for Valve's Proton, even thought it's basically the same project, 2 different culture, Valve doesn't care if the experience is worse
