> Half of the metro areas in the US used to have comprehensive public transit!
Sure, when said metro areas were a 10th of their current size with a couple orders of magnitude fewer residents street cars were kind of a thing. You cannot credibly expect a similar system to service the suburban sprawl around Atlanta for example. So unless the plan is to dragline the suburbs and mulch 80% of the urban population this is a complete non-starter. The sheer number of routes and volume of equipment required to service them would be financially prohibitive.
So many americans are seemingly utterly ignorant of their own history and then use that ignorance to insist "It can't happen here"
Go read up on the tram systems we used to have.