STARTTLS is client-to-server (or at least node-to-node). RCS node-to-node is already always encrypted. E2EE is like both sending and receiving parties agreeing

STARTTLS is client-to-server (or at least node-to-node). RCS node-to-node is already always encrypted. E2EE is like both sending and receiving parties agreeing to use PGP. The servers aren't involved with the details; they just move the opaque bytes.