BTW, this is the way: Assuming nothing exceptional, with the every-half-hour or better frequency, I use Waymo to get to a Caltrain station, take Caltrain to a nearby stop, and then Waymo from there to destination.
It would be dope if the Waymo app, given that it knows the travel times via Google maps transit and your location, could arrange this for you so you walk right into a waiting Waymo the moment your train arrives, and the whole thing could be routed as one trip in the app.