It is
their market to regulate.
And right to repair is very much a part of EU regulations. Without those regulations you'd be in a far worse situation.
https://single-market-economy.ec.europa.eu/sectors/automotiv...
If BMW idiocy gets you upset: don't drive BMW. My car is 25 and I can do just about anything I want on it. Your beef is first and foremost with BMW, and I'm fairly sure that if the EU deems this kind of behavior anti competitive it will be smacked down, even if the participants are all EU based.
You seem to want regulation to be perfect, but in light of manufacturer abuses it's a catch-up game.
https://www.automotiveworld.com/articles/how-far-will-the-in...
Is a good article on the subject, it also helps to see that there is a fine line between what has to be made available and be subscription free and where manufacturers may have some leeway.
I agree with you that changing out a battery (which is a pretty common affair) should never require a trip to the stealer.