I don't really get that. Where I lived in Italy had about 300,000 people in roughly the same size area as Bend (less than 100K), and I thought it was a pretty nice place in a lot of ways. We didn't have a yard for the kids, so we went down to the local park with them, where they saw their friends and we'd get to chat with parents. Because most people live in towns, they're able to protect some natural areas close to the town that I could ride my bike to.
I get that some people really want the 'country' experience, but then you shouldn't live in the middle of millions of people (the bay area). There are shit-tons of small towns with lots of cheap-ish land outside them that are nice in their own way.
By letting cities be cities, we get to protect more land, which I think many of us support.
Sure, Peninsula is expensive, but its proximity to jobs is the major driver of its housing costs.
You can have all that and more in Salinas or San Luis Obispo, but you’ll find that the lack of jobs makes property values far lower.
You don’t have to tear down parkland or pave the horse trails to allow a few more large apartment complexes next to the already noise-polluting Caltrain line.