It takes a lot less work to meet up with friends when everything is a 20 minute drive vs. when everything is a 2 hour walk to bus to once-per-2.5-hours train to bus to walk. In the Bay Area, seeing friends who don’t live in my neighborhood is a special occasion. In car-oriented Midwestern sprawl, it was almost every week. Being in cars together, trading rides, etc. also created a pleasant, low-pressure space for conversation. The audience of one’s fellow train/bus passengers changes that dynamic a lot. I don’t think it’s as drastic a difference as you say. There are tradeoffs all around.