- Game used to be Mac playable, but isn't because of 32-bit
- Game doesn't have a Mac version at all
Valve's work on the Steam Deck shows they could fix both problems but why should they do free work for the world's richest corporation?
I don't think galve trusts apple to do anything different at all - apple maintains much more stringent control of their os and what software can be run on it, and also asks for platform fees.
Valve wants none of that. Apple will develop their own game support and it will be for an apple gaming platform that they'll take 30% for.