Yesh go to literally any other industrialized part of the world and see how ** backwards the US is on trains

I’ve become quite radicalized on trains after visiting Japan and Switzerland myself.

Bus Rapid Transit is another option that could be amazing (while being much cheaper to implement), but it falls short for the same reason as trains: they require dedicated infrastructure that complicates driving, and complicating driving is political suicide.

None. Why would you think that? My guess is you're an American living nowhere near an urban rail system but I thought most people here would at least be passing familiar with modern trains. Even some American cities have them.

Also just like... looking at a train and noticing it can carry a ton more people than a car, has no concept of traffic, and can theoretically go as fast as possible.

What makes you say that? I'd only propose them in very high density corridors (or in corridors where building a train would be paired with allowing high density).