That's making the assumption that we only have a static screen to place them into. In VR, we have the entire environment around the screen and potential for a HUD locked to the user's eyes in space. It would be cool to try different implementations and see which experience is best.

Anime sometimes have unorthodox subtitle placements, it can be nice and also annoying.

Maybe it is a getting used to it thing, but it can be overwhelming.

If you want to recode all captions... Captions are coded to be rendered in particular places on the screen. It's a lot of work.