San Jose is a rest and vest type of vibe. Not much in terms of actual cool new stuff happening there unless hanging out with other big tech folks and talking about work nonsense or your new Model Y LR is your thing.
SF on the other hand is definitely a hotbed of startup activity. People are working on AI startups. People are networking and discussing new products and services. It’s a good mix of young people and experienced folks mingling with each other to find something valuable to work on.
The vibe I get is sort of.
The funny thing is when I was in SF last, most people downtown were flying in to meet their teams at a SF office. Not many people actually commuting there for their job regularly. Hotel lobbies seemed full of teams socializing for their team "onsite".
So its maybe the central place to travel to for facetime