A country that's going to mandate backdoors/access to such communications, are going to outlaw communication methods they can't backdoor.
Say Apple makes a federated end-to-end encrypted messenger app, the government will still go to Apple and say "let us read all the messages, otherwise you can't sell your devices". THAT is the problem, and it can't be solved by more technology and shouting "BLOCKCHAIN!"
A country that's going to mandate backdoors/access to such communications, are going to outlaw communication methods they can't backdoor.
Say Apple makes a federated end-to-end encrypted messenger app, the government will still go to Apple and say "let us read all the messages, otherwise you can't sell your devices". THAT is the problem, and it can't be solved by more technology and shouting "BLOCKCHAIN!"