They are, and should be, huge time saver outside cities. But city centers? Those should be on purpose as annoying, time consuming and costly to regular traffic as possible. It should be only necessary services, taxis, public buses and so on.

Here is the place for a good public transport, even in US it should be trivial to make it financially self-sufficient and attractive. People always choose whats best for them (cost or time wise). European city centers work like that and everybody normal accepts that.