It's mostly for youtube shorts that don't get a ton of views in the first place, so I am going for a quick and easy fix that keeps the file size mostly the same.

But you are of course right, if I would go for a professional setup I would not recompress it

That is the onboard recording feature of the Meta Quest, it does have a way to change the video codec but the audio codec is fixed.

I'd also argue that most off the shelf stuff that records videos in any form uses AAC as a default simply because it's ubiquitous and thus has great cross compatibility.