Mass transit includes buses and light rail, both of which are no-go zones in these declining cities.
Subways, like New York City, while less common, are also in decline.
I fly into Atlanta frequently to see family, who are arrayed in the suburbs north of the city. Years ago, the kids would say - “take MARTA and we’ll pick you up at X station”. Today we refuse to visit unless they pick us up at the airport. Too many scary encounters, winos spilling liquids on you as you ride, rapster thugs making noise and being rude. Fuhgeddaboudit. I’ll never ride that mess again.
Due to type of leadership rather than presence of buses and trains, which as I mentioned earlier ought not be owned and/or operated by the government. The only type of “public transit” that exists in Detroit, for example, is buses.
The removal of electric trolley cars (today misnamed “light rail”) and replacement with buses was once sold as a way to remove such type of transportation from the hands of monopolistic utility companies and into the hands of private bus operators, ironically enough. And once they “failed” due to government policies, right into the public sector they went.