> (i.e. loud and busy environments with many strangers, often physically closer than comfortable) is unnatural to begin with.
What is unnatural about this? We have plenty of anthropological evidence that humans have been doing massive festivals for at least many thousands of years i.e. people voluntarily gathering together with strangers in loud and busy environments with all sorts of sounds and smells.
For one, when and where this was the case, it was probably once a year or so.* Not daily or weekly.
Furthermore, the "voluntarily" bit plays a big role as well. If I were to go to a big festival (as you can guess, I wouldn't), then I guess I would be fine with the people. But that's not the same as commuting IMHO, where I'm together with lots of people involuntarily.
* it's an interesting topic actually, so if you have any sources, I'd like to read them.
We have anthropological evidence that humans lived like sardines in a can 24/7? Where?
Ah yes, that natural many-thousand-year-old massive festival tradition we all know and love: the twice-daily subway ride. Good comparison.
We still have festival type experiences: concerts, street festivals, gatherings in a park, church, etc. None of them particularly look like the bus.