Stuart Varrall observes something about the visionOS apps that he has seen so far:
However to me this has resulted in many of the apps I've seen lacking a distinct character. Their screenshots appear bland, making it challenging to distinguish one app from another.
It’s super early days for visionOS design, as Stuart also notes, but in my experiments with the simulator, I have noticed it’s harder to use colour effectively in the semi-transparent “glass” environment than it is on iOS or macOS. I believe this may be the underlying reason many apps have a similar look so far. What I’m confident of, though, is that developers and designers will get the hang of it, and Apple will make adjustments where they are needed, too.