The thing about E2EE is that it's not something that you can meaningfully ban in a non-totalitarian society. RSA boils down to one fairly simple formula, for example, or a Perl one-liner. People who really need it will figure it out.
Besides, there would be quite a few people who'd be actively circumventing any such law if it were enacted, e.g. by hosting the apps in other jurisdictions. And I think that's a good thing! There should be fundamental limits on the power of governance, regardless of how democratic said governance is; and democracies can be no less abusive than other forms when it comes to minorities etc. Or even majorities, when established public mores essentially require widespread hypocrisy - the Prohibition comes to mind. "Think of the children" (or terrorists, or whatever is the go-to political excuse at any particular moment) is not a valid exception.
Besides, there would be quite a few people who'd be actively circumventing any such law if it were enacted, e.g. by hosting the apps in other jurisdictions. And I think that's a good thing! There should be fundamental limits on the power of governance, regardless of how democratic said governance is; and democracies can be no less abusive than other forms when it comes to minorities etc. Or even majorities, when established public mores essentially require widespread hypocrisy - the Prohibition comes to mind. "Think of the children" (or terrorists, or whatever is the go-to political excuse at any particular moment) is not a valid exception.