[sir-alien]

The problem is that with physical telecoms providers, you can mandate these LEI implementations. If the provider doesn't comply you ban the sale of the device. Yes, you can get a few black market devices to get around this but you can't head into your local shop to obtain it.

With the current scale of open source software, you can mandate a law for backdoors but countries that do not have such laws would be able to remove these backdoors from the open source software if they are ever put in. Simply banning OSS won't help either since many countries that have banned encryption still see widespread use of encryption software as the internet has no borders. Firewalls don't count because that is equivalent to trying to stop a million tunnel diggers from digging over the border all at the same time with a million more diggers ready to go. Ask China with their great firewall full of holes.

Backdooring or banning major providers like WhatsApp, etc will only push more and more people to an open solution that is globally distributed.

The only solution to gaining encryption access is the simple option. The option that if you are an interesting enough person, will get to play catch with a wrench while your hands are tied.