Earlier quoted context omitted.
If only the ecosystem had been built to use E2EE by default, always. They fucked up with the design allowing bridges and bots, left E2EE for later, and now they're in the vicious circle of downgrade attacks until all major clients switch to E2EE with no insecure fall-back option.
there aren't downgrade attacks. we turned on E2EE by default in May for private rooms, and there's no negotiation involved. if you're on a client that supports E2EE (i.e. almost all major ones, now) and you try to DM someone, they simply won't be able to read you unless they support E2EE. i.e. they can't downgrade the convo.
My only big issue is that the iOS client doesn’t support multiple simultaneous identities.