Oh definitely, that's why I highlighted the lack of innovation in browsers for handling keys and encryption/decryption. This all needs to happen locally (not the trendy thing these days) and the current tools aren't at the level where that's going to happen at a large scale.
There would still be the key-exchange problem (I can't imagine a system that would make it easy for non-technical people to exchange keys out of band, even if you could explain why that was necessary and what it means), but with good browser tools I bet the number of zero-knowledge type sites/p2p networks would explode.