Then criminals should focus on what that non interesting stuff is likely to be and exploit that.

Terrorists (as well as a CIA director) have for years used a simple trick to communicate without leaving suspicious looking metadata: https://www.washingtonpost.com/news/worldviews/wp/2012/11/12...

I find this type of legislation works like DVD copy protection: the innocent and non tech savvy will be disproportionately affected and it won't do anything to deter those with sufficient knowledge.