Canada

The mandatory backdoors would not help with this problem even if they were somehow magically made safe. If they managed to coerce Signal into installing a back door — which of course they can't do — it would quickly be abandoned by its users and whatever tiny share it has of all the criminal gang recruiting activity would move on to places that are even harder to monitor.

Telegram users, where more of that sort of thing goes on, would probably be slower to move. But still people would eventually catch on and there are already more secure alternatives waiting to take over. They'll just be ensuring that whichever one wins out won't be one that's in any way cooperative with Canadian law enforcement.

Don't worry, the criminals will be fine. It's only the normal people who don't pay any attention to security since they have nothing to hide who will become super easy to spy on.