Even within the Larger Bay Area there is plenty of smaller cities with a well developed and prolific downtowns that have startups, retail, supermarkets, bars and restaurants all within walking distance of a rail system connecting you to SF:
Mountain View, Oakland, Redwood City or where I live - San Mateo.
My family and I have been a 1-car household for more than a decade and mostly walk everywhere including a train station for a 25min ride to SF
I've only visited Silicon Valley once, so my impression may be skewed, but to me it came across as this incredibly bland, entangled sprawl of anonymous strip malls, with each "city" indistinguishable from the next.
To some extent these cities seemed walkable, but in practice everyone has a car, and most endeavours have you end up on the highway. Everyone seems to complain about either traffic or about the awfulness of BART, but maybe that's HN.
I did love SF itself, though it seems to be in a similar situation as NYC, nestled deep within this huge web of urban sprawl that you have to punch through in order to get out into the wilderness.
Bay Area is a large metropolitan area, so yes, there are places like what you described.
There are also great cities with walkable downtowns often right next to a train station. You can choose to live close to these areas and enjoy walkability, or live a bit further and drive everywhere.
There are definitely choices
