The US is very young and not dense, save for a few downtown clusters.
There is definitely a lot that can be done, but it really comes down to user demand. People actually prefer cars if it’s the viable option. But depends on distance, timing, distance, and goals.
We shall see how ridership shifts in Los Angeles - probably the greatest live experiment in trying to force habit change currently in progress. Anyone here have inside baseball numbers on the habit changes in LA?