if the amount of human and financial capital invested in ridesharing and autonomous vehicles was instead invested in mass transit in the US, nyc wouldn't be the only city in the nation where not owning a car is a (legitimate, long term) option without sacrifices
I seriously doubt that. The amount of money that has been invested in autonomous driving is low tens of billions. It's the same order of magnitude as the cost of extending BART to SJ.
That's a good project, but it's just one. It would take vastly more money to actually make public transit great in the US, especially in many cities at once. I think the amount that has been privately invested in self-driving cars seems small in comparison.
I guess I just don't understand why you'd say they prevent cities from improving public transit.