All these comments about metadata not being useful are missing the point. Metadata is incredible valuable and sometimes just as valuable as the decrypted data itself. Knowing what sites a target visits, access patterns, changes in behavior: all this can be fed into ML algorithms to come up with fingerprints. You don't need to be able decrypt the data in transit if you know the endpoints and can somehow compromise the…
And that is only speaking of something within the Rule of Law (accessing metadata with a warrant)...
Outside of the Rule of Law, people have been killed for metadata.