Most of the heavily populated places in the bay area are fairly flat, so that's not really a problem. Plus, with ebikes these days, hills just aren't the barrier they used to be.

The problem is mostly just infrastructure. Almost no California cities have more than a piddling amount of safe transportation biking support.

These days have little to do with historically. The bay is hemmed in by hills and water. LA is similarly hemmed in, creating a nice bowl that traps pollution. Seattle and Portland are both hilly, you are not at a flat grade. Berlin, Amsterdam, Copenhagen are all flat in contrast.

Cities with lots of hills in Europe don’t have as many bikers or biking infrastructure. Eg Lausanne unless you want to go for a jaunt by the lake. Cannes was the similar during a short visit I made 20 years ago. Hilly south Europe (Athens, Rome) doesn’t seem to like bikes very much either.

Good thing we’re talking about ebikes with great torque that make short work of hills, right? LA is ten times less smoggy than when I was a kid, thanks to cleaner cars and no electric vehicles.

Should be "also electric vehicles."