I think you're jumping the gun here.

An account is supposed to belong to a single person. If you are able to definitively prove that you are that person (for example, by showing up to an Apple store with your ID card), you should be able to restore access to it. An abusive partner won't have access to that.

Refusing restoration when someone else has access to it is understandable, but it works the other way around as well: an abusive partner would be able to prevent the legitimate owner from accessing the account.

I think it's far more likely that Apple just can't be bothered. Dealing with stuff like this is messy and complicated, and they aren't going to lose any revenue from those few thousand people a year losing their account and all their data.

> An account is supposed to belong to a single person.

Supposed to yes. But in practice there are WAAY too many adults giving their kids devices without a specific child account. People have shared FB profiles ffs.