And yet here we are. If they won’t compete with each other, regulation would seem the answer to this crap (as the original poster proposed).

This is often raised as a caveat when a business does something anti-consumer.

Maybe it's worth accepting that businesses will not behave as you expect.

Markets which require billions of dollars to compete in are not truly competitive. They may be competitive in a regulatory sense, but not in a practical one. And these markets have huge amounts of regulation as well that limits competition on top of the financial limitations on competition.

The slim margins in the automotive sector would like to have a word with this argument.

The 14.8B € profits in 2022 would also like to have a word with your "slim margins".

Slim margins say nothing about competitiveness. You can lose money in uncompetitive or competitive markets. You can have huge margins in competitive ones.

Also I don't think the 10.5% profit margin of Mercedes is low - the average for the S&P 500 is 11%.