[potatoz2]

That's largely true, but many parts of Paris itself are relatively working class (the 13th district, the 19th district) and still very dense.

Similarly while the outskirts of Paris don't have a subway system (they have the RER, akin to BART) they are still very dense.

Walkability comes from density almost inevitably because it's financially doable to have more stores/activities/restaurants in a smaller space while still getting customers. This makes walking around the city interesting.

I think the issues in the Bay Area cities I know relatively well (SF and SJ) comes down to political will to zone neighborhoods properly.

[jelliclesfarm]

There is also some politically correct diversity quotas. In the bay areas, they think the local school teacher as well as Starbucks barista should be able to live in the same neighborhood as a FAANG millionaire. Naturally, this creates NIMBYs. It’s human nature.