performance of javascript cannot match c++.
Wasm helps. you also need state of the art decoders. And really, full GPU compute access.
streaming will be a problem for awhile to come. youll want to download in advance, something that the web is not yet set up for.
It’s doable, certainly. But the web will make most things harder. When smartphones came about h264 was already quite far along in adoption (released in 2003). VR video is not at that state.
Maybe Apple has an answer for all this. But I don’t think so. VR video is still under development.
By the time VR video is reasonable to do though, i expect things to progress on the web quickly, maybe lagging 6months-year.