Different market, I think. The PSVR2 is aimed at gaming where resolution matters less but the demands on graphics hardware to push that resolution are much higher because they're rendering complex scenes with fancy visual effects and fast motion, all on a console that's limited in graphics power compared to higher-end gaming PCs. Projecting mostly flat windows with little overdraw is much less graphically demanding; the SimulaVR folks and others experimenting with spatial computing have even managed it using the integrated graphics on low-power Intel CPUs, though admittedly with not quite as high a resolution as Apple.
Yeah, I actually wonder if 4k ends up being as good as it sounds in practice for the use-cases Apple are pushing.
A 27" 4k monitor in real life should look better than a virtual 27" window pushing the same resolution within the 4k display of the headset. For stuff like text that's going to have a corresponding loss in sharpness, and because you could be seeing something at an angle there's going to be lots of weird aliasing effects. There's a reason why Apple starting pushing 5k monitors.
I'd guess the tech would need to get to 8k+ for each eye before it starts feeling "really good" for these use cases.
I feel like they have their "game porting tool" out now, because they want to drum up games for visionOS, so it's likely that they'll also do gaming if they can.
The PSVR2 also does foveated rendering, which the Vision Pro does not seem to do, which is about the biggest disappointment about this. I don't care about millions of pixels in the corner of my eye eating up my battery life when I can't even see them.
