The entire market for Uber was because it cost less then Taxi's

People have this mythical believe that prices are infinitely elastic and that all uber drivers can magically make 100K a year with out causing the company to fold

That is not how any of this works, as service like you are talking about has been around for decades, they are called black car services. They employ professional drivers at reasonable wages, they DO NOT however have a mass market because the costs of those cars are $$$$$$ and only people in the Upper income levels can affords to use such a service

When Uber started (then called UberCab), they weren’t cheaper than taxis. They instead were more convenient (no trying to hail a cab, no fighting drivers over taking cards, no expectation of tip despite subpar service) and consistent. I miss those days.

If you can automate part of it with an app it could be cheaper. Maybe it won't work out cheaper than a taxi, but pretty likely cheaper than those black car services. And since there is a market for the latter, there might be enough market for something in between; I don't know how large.

So you believe the booking is the most expensive part of running a professional car service? and that by automating the booking they would cut costs significantly?

Really?

In the UK, they have already automated it. Many cab companies allow booking by app, with a _similar_ experience to Uber (though with worse service, usually).

Importantly, they charge the full meter price as set by the licensing authority, and engage in the usual cab of tactics arguing about credit cards, taking sub-optimal routes and espousing disagreeable politics for the entire trip.

This is simply incorrect. Black car services are just as unreliable as cabs in many parts of the world (and in many others, the distinction does not even exist).