It gets on my nerves that people use WhatsApp or Signal or Threema or Telegram or whatever hip new thing they came up with for instant messaging because "it is too hard/weird to create an XMPP account".
XMPP is a protocol for federated instant messaging in case you never heard of it.
If we are already getting people to use Mastodon instead of birdsite, how about we made it really easy for instance owners to also run an XMPP server using the same credentials as Mastodon for user authentication?