Sometimes, privacy is at odds with features. That is why those devices would no longer be marketable as "regular smart glasses."

But at the same time we need to make medical vision devices that are exempt from those bans because they give strong privacy protections to the passerbys.

No obsession required.

An advantage of a standalone unit is you can take it with you, or for people who don't already have a gaming computer.

You're also asking why not have it plug to a more powerful machine. The answer for that is simple: wires get snagged and pulled on, in practice it's a poor experience (remember, you cannot see the wires when you are wearing the headset).

This lets you throw away and start over, but also gives you infinite undo even after "loading" an older version.