Just from my head:
IRC, XMPP, Matrix,
SMS, RCS,
Session, SimpleX, Nostr, Jami, Tox, OnionShare, DeltaChat, Sup., GNUNet Messenger, Mumble, Zulip, Briar,
Signal, Wire, Threema,
Snapchat, Telegram, Facebook, Facebook, Facebook, Discord, Slack, iMessage, Google Chat, Twitter, KakaoTalk, WeChat, GG, TeamSpeak.
This post is not for discusson which one of standards, networks, services or garbage is the best for anything. This is a call can we just stop making more?
No. I will make a new one just to annoy you.