Users choose their technology. Technology doesn't choose its users. There's no way to make it impossible for criminals to use some communications service. The same technology that protects the lawful person will protect the terrorist and drug dealer. There's no solution available that doesn't also involve sacrificing the safety of upstanding citizens.
In case anyone doubts the above fact: government agents abuse their surveillance powers to spy on their loved ones.
There's no reason to believe the government is any better than these criminals. Cryptography must be strong enough to defeat even intelligence agencies as well as ubiquitous so that it'll be hard if not impossible to enforce legal limitations or bans.
In case anyone doubts the above fact: government agents abuse their surveillance powers to spy on their loved ones.
https://en.wikipedia.org/wiki/LOVEINT
This article was posted here recently, a reminder of how easy it is to become the target of warrantless government surveillance:
https://schmud.de/posts/2020-06-02-mlk.html
There's no reason to believe the government is any better than these criminals. Cryptography must be strong enough to defeat even intelligence agencies as well as ubiquitous so that it'll be hard if not impossible to enforce legal limitations or bans.