The Oculus Quest has games that directly target it on its on platform. Most Steam VR games expect a PC with a reasonably, powerful GPU. Macs don't even run Nvidia GPUs
Most of Apple leadership just doesn't care enough about games. Sure they care a lot more now, but imo still not enough at the detriment of the Mac line. imo Jony Ive placed too much of an emphasis on form instead of function for AR / VR. If Mike Rockwell won the internal politics at Apple for his separate VR hub, maybe we'd have well supported VR for Mac by now... but nope.
The Oculus Quest has been doing VR acceptably on mobile _phone_ GPUs for 15 months.
A recent Mac laptop's GPU should be able to handle at least as good an experience as the Quest.