E2E is just one part of the puzzle, you got to have a open source P2P or federated architecture as well, otherwise you have to trust nebulous company or person intrinsically. People change and companies can be bought, but you will be stuck with their platform in order to contact your acquaintances, and changing that means loosing your contacts.

That is why the DSA is important. But you will be even better off just directly choosing a chat platform, where the users are in control.