To your last point, my read on the history of taxis in the USA is that that was roughly what was happening during the early 20th century, until some regulation

To your last point, my read on the history of taxis in the USA is that that was roughly what was happening during the early 20th century, until some regulation came along to create artificial barriers to entry. Uber broke down those barriers to entry, which allowed them to disrupt the incumbent taxi companies. But it also means that there's not much to protect them from being disrupted themselves. The taxi situation in most cities was awful before rideshare came long, and the taxi cartels' rent-seeking behavior produced produced some gross externalities (the lack of any train lines going to LGA comes to mind), so this has perhaps been a net benefit to consumers. But Uber and Lyft are not charities, and that fact has no bearing on their viability as businesses.