So, in other words, any law is a bad law if it is not exactly like in the US? To hell with the fact, that European countries are in general democracies? And more direct than American at that (direct election, not through electors)?
Yes, some jobs are "closed" in a way in Europe, with huge differences between countries. But, pathological examples aside (and they do exist), they are only closed in terms of setting prerequisites and perhaps taxes - very far from a cartel. In this case:
- As long as you are legally allowed to drive and do not make a profit from it, you're free to arrange cost sharing with passengers - it's eco-friendly and good for the traffic.
- If you are healthy and have extended insurance, register and you can carry passengers for profit on prenegotiated routes.
- If you are healthy, have extended insurance, probably pass an extra test, maybe something else as well (I'm not German)... In other words, if you meet all the requirements, you can register as a taxi driver. Now you can not only carry passengers for profit, but also use taxi stops, pick up chance passengers from the street, use taxi lanes, etc. No, you do not have to be related to a taxi driver, bribe someone, etc. Just meet the requirements and register.
So, what do you call a free market? One where only the price and reputation decides (remember that reputation does not scale very well)? Where first encounter with a service provider is by definition a high risk? Sorry, I actually prefer to know that if I get in a taxi with the official sign, I know that the driver is a professional, knows the city, the car is in a good condition and if anything happens anyway, the insurance will cover it well above the limits set for regular drivers. Or not, but a driver carrying the taxi sign illegaly risks a lot (at least a large fine or even jail time).
Feel free to run your country anyway you like, but please be cautious about telling others that their ways don't make sense. Most choices in like are multicriterial optimisation problems and there is no clear ordering of Pareto-optimal solutions.