It doesn’t matter if you think a thing holds no value or not. You might be doing something that is currently legal and socially accepted, that on a whim could turn into the worst crime ever. Why would you give Facebook or whoever information that you did it? Why do they need to know? E2EE is obviously something that is doing its job in keeping people free from surveillance or otherwise governments wouldn’t try to ban it.

TL;DR: You are better off keeping as much as possible to yourself in general.

Edit: typos