The requirement that amazes me they never gone absolutely done for was that to get certified (to carry the Play Store) you must not release any Android devices which are not certified.
i.e. a given manufacturer would not be able to sell Google based Android devices and separate non-Google based Android devices.
It's as if being able to bundle Windows OEM licenses was reliant on not selling any models with Linux.
As long as it's not sold as "Android" to the mass public I don't think there is a meaningful problem. For example, if you go to the trouble of hacking the Play Store on to a Kindle Fire you do know it's your responsibility if it works or not. Google would probably tacitly approve because such activity reduces the need for the Amazon App Store.
I didn't think Huawei had released a certified Android device in many years now, as I don't believe Google would be allowed to act as a supplier to them even if they wanted to.
Back around the Nexus 6P they probably got an exception as Google tried to promote more competition for what was rapidly turning into a Samsungopoly. Samsung later themselves negotiated a position where they could make other changes in ways Google didn't approve of, and that was by leveraging the threat of going all-in on Tizen.
Perhaps not "absolutely done for," but there was meaningful action here that resulted in a 4.3 billion EUR fine (of which only 200 million was reversed on appeal).
The action was based partially on the Anti-Fragmentation Agreements (AFAs) mentioned above: https://www.clearyantitrustwatch.com/2022/09/the-general-cou...
IMO there should be mechanisms that prevent this kind of thing from ever occurring, but regulating this in a way that doesn't meaningfully impede other (benign) certification programs is a complex design space indeed!