This is why you shouldn't trust experts on stuff outside their speciality, this answer is just wrong.

You don't even need to research it, the lived experience of being in a dentist office with mixed oxygen and nitrous produces the recreational effects - if it was mostly hypoxia, having oxygen mixed in would have a greatly diminished "recreational" effect.

I mean, it is true most people doing it recreationally are giving themselves mild to severe hypoxia, but that doesn't mean the effect is caused by hypoxia