The low population density is arguably caused by the bad planning.
>make it a place ill-suited to public transportation.
I'm quite convinced that you will not be able to drive yourselves out of the issue you have in the U.S - you'll need to retrofit what you have to make it amenable to proper public transportation. EVs help a bit, but only really with the carbon dioxide-issue - everything else bad about cars is still bad with EVs.
Here in SW Ontario there are countless people riding those electric scooters or ebikes in the summertime. I’ve even seen old barflies hop on after drinking a pitcher and head on to the next spot. I’m sure the Bay Area has more clement weather year-round than here.
Maybe Caltrain did marginally better? They added express services not that long ago.
Long decades of poor planing in the US (and in general the low population density) make it a place ill-suited to public transportation. EVs affordable enough for the poor will definitely be required here, so here’s hoping you’re right and we’ll reach that point soon.