My daughter was mainly a bus rider, as the places she usually goes aren’t served by the subway. I used to ride the subway to work, but I haven’t in years since I’ve turned to working from home.
My theory is that traveling in a vehicle that is “on rails” (train or tram or bus - they’re all alike in that their routes are predetermined) removes every bit of agency from the passenger, and leaves them completely disconnected from details of the route. Passengers engage in conversation or bring entertainment with them that further weakens the spatial link.
Those traveling in private cars have at least some opportunity left to influence their trajectory or destination. “Perhaps you should make a right turn here” or “let’s stop for ice cream at that place we like” are both things that get said along the way. There’s also the constant stream of teachable moments supplied by other drivers in the form of poor vehicle control.