If by 'downhill' you mean 'their business expanded massively and they became a global phenom', then yes. They were never necessarily professional drivers, and

If by 'downhill' you mean 'their business expanded massively and they became a global phenom', then yes. 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.