If an icloud account becomes in dispute then it should be locked, generally. The problem isn't the technology it's the lack of actual tech support. There should be a reasonable way to speak to someone that can validate the account in someway. Similar to credit reports. Show an ID, answer questions about the account, like previous devices, when it was created. Provide pictures etc of the people in the pictures in the account.

The problem boils down to one of the most profitable companies in the world becoming that way by cheaping out on support for their users.