I've lived in large cities, but I found the more ideal circumstance was a small but urbanized town - after I lived there 8 years or so, I not only had the good friends but an enormous group of casual acquaintances. So I literally ran into people I said hi to every time I walked anywhere. In fact, at various times most of my good friends moved away, but the whole group was there. It was east coast, so like one time someone left a pot of soup on my stove. I don't mind noise, and the neighborhood wasn't too dirty. It did have people of various income levels, and was cheap enough to have artists, who both put up many beautiful things and had a certain tendency to clutter. Also a lot of biologist types, so they had lovely plants planted, which was nice.
I'd rather have people I trust a bit around me than privacy, in general. For sure people there help each other out when help is needed. It just feels to be a more resilient, robust to errors kind of society than me and my stuff out there.
Now I'm living in San Jose, but I've passed the 8 year mark in my current location and in fact am accumulating connections with the people on the block and nearby. I go to stores where the workers stay year after year, so I am familiar to people. I've started going to classes at a local university. It's still not the connected feel of a small East coast town (Californians do seem to like their fences around the backyard and not to appreciate comments on their personal decisions), but pleasant. If only there was a grocery store I could walk to.