By using badly maintained, very old vehicles, with low to no enforced standards of operations for safety.
By operators exploiting themselves because of only coarsely tracked costs and low level of reserves.
By not having to conform to strict schedules and not providing service in off hours, only when good business is expected. This makes the infrastructure virtually nonexistent, hurting the general economy by limiting the possibilities of those having to take these forms of public transport.
By applying demand based pricing, for example when working off hours charging more to cover the running costs which are split among less users.
By not working for peanuts, it is your false perception because you have far more income (and disposable income) than those who have to live on incomes local to that area. If PPP adjusted it is often quite a sum.
Just to name a few factors. In general well run welfare states, or at least moderately well run authoritarian states (also having some welfare aspects many Americans would probably call communism) tend to have good public transport, for different reasons, and share taxis are generally not considered a good public transit.