On the East Coast home buyers have started to discover that all these previously neglected walkable little colonial & 19th century towns and denser suburbs, often adjacent to rail lines, have a lot of value. The smarter municipalities have been taking the hint and zoning in denser development to grow out the town center naturally as it was intended. The east coast can start to regrow a lot of the character that was lost in the 20th century tract housing boom, and begin to resemble the old world in that way.
On the West Coast, most of the small suburban cities never had a town center to begin with. They were designed by real estate developers using standardized high-profit low-density building plans, entirely focused on cars over walking anywhere. (God forbid you live somewhere that you can walk to buy groceries!)
So you end up with these awkward community layouts where there are zero denser centers to grow out of naturally and permanently zoned that way. Nobody wants to take the plunge in having their house re-zoned and experiment with the costly home investment they're sitting on. Mixed use is still a dirty word. So no change occurs.
All that seems to be getting done lately is locking down neighborhood zoning and building fancier and fancier shopping centers. Something in this is going to change eventually, but unless people voluntarily bulldoze their houses to make room for new town plans, I can't imagine what form it will take.