It's pure malicious compliance from Apple. Anybody defending Apple on this is simply delusional.
Browsers with alternative engines can be offered in regular AppStore. That's why I wonder why isn't this a thing. At the end of the day, browser makers probably want to reduce confusion and complexity of maintaining two vastly different applications under the same name. This most likely isn't a case of malicious compliance, you got yourself carried away here I think.
ETA: your link includes JIT; I’m pointing out that that’s why they don’t exist outside of the EU. Non-JIT browsers would just not be very performant.