Waymo's usually something like 50% more expensive than Lyft in SF, in my experience. But the drivers don't tailgate, have colds, listen to your conversation (AFAIK)...I'll generally opt for Waymo now if I have a choice. The biggest problem I have is that it's usually a longer wait due to the smaller fleet size, but if I'm planning ahead, I'll just book one for a given time, and that takes care of it.
Lyft from MV to SF is like $100 I think? It's definitely not enjoyable but for Bay Area prices it's not ruinously expensive.
You /should/ be able to save by using shared rides, but in practice when I tried the driver was so mad they just dumped me on the side of the road and I had to call and get a refund.
The new Caltrain schedule isn't half bad though, if it came twice as often on the weekends we'd be cooking.