Regulation also entails that regulations get enforced. In that case that means regularly checking the taximeters.
Here in Germany taximeters get checked once per year. I never heard any complaints from anyone here about taxis trying to rob you off.
If I search in German for manipulated taximeters I mostly find articles that are about foreign countries.
I paid 90 euro for a taxi ride from the airport to downtown Munich. It should have been 50 euro. I am pretty sure that wouldn't have happened with Uber or Lyft.
Here in Germany taximeters get checked once per year. I never heard any complaints from anyone here about taxis trying to rob you off. If I search in German for manipulated taximeters I mostly find articles that are about foreign countries.