That’s an article about the unwanted side effects of monopolistic tax cabs.

In a competitive market, this should happen much less. And the big innovation of ride sharing is it gives a valuable tool to drivers judge potential fares with besides their appearance or pickup location, specifically their rating.

Free markets don't solve racism. The "monopolistic" taxi cab company had numerous individual drivers, each making a decision. Moving this monopoly to Uber and Lyft doesn't work. And no stars are going to override bias.

Your assumption is that the bias is only racism, when sometimes it’s racism and sometimes fear of being robbed/assaulted. Stars definitely curbs the latter.

I don't think being robbed by a passenger is a reasonable fear - after all, the app has their location, both start and end, their credit card info, and their phone number. Criminal activity by passengers is easy to catch. Fear of crime in this circumstance is reasonably other, unrelated people, which stars does nothing to prevent.