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?
Do you want them to stop innovating entertainment too?
If they did what you asked, there would be 100 asking why we haven’t figured out news ways to do this or that. “Why are we still watching movies from CD?!?”
Answer is no. They won’t stop making more. That’s how innovation works.