If the Vision Pro can replace my Mac, I would buy it. I'm not going to buy this if I still need a separate Mac. I'll get a nice monitor then instead.
It has a M2 in it. So theoretically possible it has everything I need. As a webdeveloper, I need IntelliJ, terminal, Docker etc.
So it either needs to be able to run MacOS natively (very unlikely). Or run MacOS apps natively and have some sort of Finder (also I don't think this would happen). OR 3rd party apps for VisionOS that would allow me to do all my work, and possibly change my workflow a little bit (most likely).
Then there is of course the current greedy state of Apple, that will probably do anything in its power to sell you this thing alongside a Mac, iPhone, iPad and whatever. In the Steve Jobs era Apple wasn't so afraid of cannibalisation.