People lived in small communities where other people were able to observe them. They were forced to interact with others through church and just basic market transactions (you go to the general store, you don’t order something on amazon). At harvest time everyone worked together to get everything done. The communities were small enough so that other people could detect patterns of antisocial behavior. That alone discouraged such behavior. If it didn’t, the community could apply social pressures to correct the behavior.

If you go into a restaurant in Sibley Iowa and leave your table a mess, people you know personally notice. If you do it in Manhattan, you can be shameless—the odds of someone recognizing you are remote, and even if someone does nobody sees you in public often enough to put together a pattern of behavior.

> where other people were able to observe them

in a very limited way, with even less tools than today. Scale is a factor but there are a million other factors in "tightly knight communities" that corrected for what you call "antisocial" behavior.

I think you mean policing. The societal worth doesn't need to be established here.

Surveillance is the act of looking for suspicious behavior with the intent to find flaws. That wasn't a requirement to a society. If anything, these ideas lead to witch hunts.

Living closer together is not just mutual surveillance. That would be quite the stretch.