So a 'malicious client' doesn't need to be part of the threat model here. And also, if you really stretch your argument, that's like saying we need to outlaw Linux and open source software because malicious actors can modify the code.

The whole idea that society demands content providers compromise ETE just because of child pornography isn't something I've heard of being 'accepted as common truth' outside of this post.

Some politicians demand it, but I thought at least amongst tech, there's the recognization that strong, *unbreakable* encryption is important.

There's an implicit obligation to build services and technology that is resistant to abuse, but that isn't an argument to not implement ETE.