Quoting: Phlebiac

Quoting: LoudTechieApple finally started nearly caring for gaming(Game porting toolkit). Also Valve has been sponsoring Apple gaming, since around the same moment they started sponsoring Linux gaming(MoltenVK), modifying open source is just easier.

Good points, I had forgotten about GPTK and MoltenVK. Both lackluster compared to what we get on Linux, but certainly positive steps. Seems like MoltenVK is on the way to being deprecated in favor of KosmicKrisp that is part of Mesa.

Apple isn't used to having to do an effort to achieve market share.
Their current market share was handed to them out of anti-trust concerns and thanks to their vendor lock in they can expand to whatever they like, usually.
Even their development they tend to leave to the bsd community. Valve wins by doing nothing, Apple thrives by doing nothing.

On the lacklusterness. Lets not forget that Mac is a very different platform than the Linux desktop.
It's not a path to freedom, it's a path to chains and protection.
Apple losing the EA lawsuits was also a boost for Apple gaming, since this slashed the prices.
For small companies that mostly make money through initial sales, Apple gaming is still too expensive, but AAA players now can make some pretty sweet money.
These AAA players also much more trust Mac for anti-cheat than Linux.