Uber started out well as your "personal chauffeur" with premium cars and polite, professional drivers. Then they started chasing numbers and valuation, and it was all downhill from there.
They were never necessarily professional drivers, and the drivers today are just as 'polite'.
The market for NYC 1% high end cars is very small compared to the value of unlocking the big marginal market inefficiency brought about by medallions.
All of that said - a bit of technology and flexibility by the world's cities and taxi fleets would have made them a lot more money and made Uber pointless.