It is wild that Apple finds it cheaper to build and maintain different App store behaviors than to simplify and make alt app stores available in all markets. Other governments/markets don't care?
"Other governments/markets don't care?"
its the least of their problems
It's a very slow process, first there is investigations, then legislation, then enactment, then enforcement which is separately a very slow process. It requires a lot of willpower to get and keep the ball rolling and in fact nobody has even achieved the full extent of what they require yet! The EU may still be years away from meaningful compliance, Japan has only taken baby steps forming a new bureau just to enforce compliance of two companies widely accused of malicious compliance.
And then there is additional discouragement and pressure in the form of sanction and trade deal threats for regulating American tech platforms.