There's a large overlap between people that want to use email as a central part of their lives and people who think everything other than text is just unnecessa

There's a large overlap between people that want to use email as a central part of their lives and people who think everything other than text is just unnecessary waste. It's not really a technical thing, but a cultural tie. Think suckless folks or the Gemini project people. I think a good argument could be made for Email being a federated, open substrate to send and receive non-real-time messages but not many people who make that argument want to see rich messages even though it's technically an easily solvable problem (albeit hopefully not the way MIME has done it today.)