As one of the resident cryptography nerds: Matrix/Riot seems to be in every way better than Telegram. I still need to review it before I can wholesale recommend it, but it was audited by NCC Group previously.
Matrix is a federated chat protocol. It is like IRC or XMPP but synchronizes history and uses HTTP-based protocol. There are bridges to IRC, XMPP, and Gitter.
It appears to be like IRC, but also integrates with Gitter, and IRC and has a identity federator called vector.im.