> Metadata is incredible valuable and sometimes just as valuable as the decrypted data itself.

Just adding an example for the people who don't see the value of metadata: WhatsApp is still a viable revenue source for Facebook even as they have no access to the text of the messages due to E2EE.

Knowing who talks to who, at what times, the type and approximate size of messages, the members of groups, and the contents of the phone book of every user gives enough information to keep their business model without exposing them to court orders asking for the plaintext (that's the reason they added E2EE to start with, there is no incentive to improve the service when they have a billion heads of cattle to milk).