The other requirements are also pretty vague and give Apple full discretion to remove browsers they don't like:

https://developer.apple.com/support/alternative-browser-engi...

> Use memory-safe programming languages, or features that improve memory safety within other languages, within the alternative web browser engine at a minimum for all code that processes web content;

> Adopt the latest security mitigations (for example, Pointer Authentication Codes) that remove classes of vulnerabilities or make it much harder to develop an exploit chain;

These allow Apple to take a security-maximalist approach and block alternative browsers that don't include the most performance-killing mitigations possible.

I don't think these points are bad per-se, but within the context of malicious compliance that Apple has already displayed, I'd be scared to invest money on alternative browser for iOS.