Private car ownership is a better everyday solution for almost anyone who can afford it, which includes the vast majority of Americans. If buses tried to compete with cars, they would lose. The only remaining niche for the bus is as a public accommodation for the poor, disabled, and elderly, or occasionally in dense city centers.

At least that’s what I think. But if you’re right, and there’s a version of bus transport that’s viable without subsidy, then there should be a market opportunity for a private business to provide that type of bus transport. This actually exists for long range intercity buses already, but you’d think it should be possible inside of some cities. I haven’t looked into this in a lot of detail but I wouldn’t be surprised if it was effectively impossible to try and start a private bus service in most cities, specifically because that would reduce ridership of city transit and threaten all of the unionized public sector jobs in that system. In which case the bus system isn’t really even for the poor and elderly anymore; it’s for the transit workers union, which undoubtedly is a player in city politics.