I think i get what he's trying to achieve: To get the bad guys (faster) by disallowing things the bad guys can use to get away with stuff.

The slippery balance is also that the good guys of yesterday are the bad guys of today and vice versa.

But both never stopped development of better, weirder, stranger and scarier stuff that can both be used for bad or for good, whichever you choose. I highly doubt encryption will stop because they outlawed it. There will be even better development of encryption that will be even harder to detect if encryption was actually used.

just a random thought, since AI can now simulate conversations, it can be used for steganography. you can hide the real conversation in a simulated one without effort.