People must be able to exchange information in a secure and private way, free of government or corporate censorship. The fact that there is no common, simple, and ubiquitous way to exchange private messages blows my mind. I wish someone would do something about it.
Oh wait, I did! Here's my attempt to implement email based on Self-Sovereign Identity: https://github.com/regnull/ubikom and https://ubikom.cc
Still work in progress, but it's fully functional. There are no accounts or domains - private key ownership is all we need.