edit: I was wrong, Delta Chat now has forward secrecy from v1.48: https://delta.chat/en/2024-11-20-webxdc-realtime
Furthermore metadata transparency can be made less problematic by using email aliases.
Furthermore metadata transparency can be made less problematic by using email aliases.
now what's interesting here is a potential future development of deltachat where SMTP is only used to negotiate the peer to peer connection, and the actual chat messages are sent over the direct connection. although it sounds kind of weird to build a chat solution on top of SMTP and then bypass SMTP in the end.
the remaining benefit would be the ability to talk to people who don't use deltachat. not needing another account on a new service. not needing to develop or maintain server infrastructure.
wait, in a way it's already there: https://github.com/ArcaneCircle/live-chat
now adapt that to storing messages... ;-)