> I think one of the reasons Vision Pro and metaverse have been struggling is because their engines are bad. Not just locked down, but hard to develop on (although I don't have personal experience, I've heard this about VR in general). If you want to build a community, you must make development easy for hobbyists and small users*. I believe this has held even for the biggest companies, case in point the examples above.
Unity and UE have pretty good VR support nowadays, and even godot is getting there. Plus making a custom engine for VR was never that much harder than for a normal 3D game (well, once some API like OpenXR got normalized).
The big issue with VR right now is that it is more costly to develop for than normal apps and games, while having less user. It makes it a hard sell. For some indie dev, I allow them to profit from a market that is not yet saturated (right now, with no good marketing, you just get buried on steam, any app store, etc).
There are many factors that make it more costly, like having to support several mobility and accessibility features for games (for example smooth and jump locomotion, reduce fov when moving the view, etc), that you usually don't have to care for in other plateform.
And there is the issue of interactivity. UX (and in many ways UI) is still very far from ideal. Most VR apps and games just try things out, but there is still a world of pattern and good practice to build up. This makes using anything VR often an annoying experience. Especially since some issue can be an absolute no-go for some user. As an example, displaying subtitle in a 6dof environment can be tricky. Some game put it at a fix point of your view, which can cause nausea and readability problem, some move still follows the head/view but with a delay, which reduce nausea issue but can be distracting and also has readability issue (the subs can go out of view).