I was recently forced to use Facebook Messenger (thanks God it's soon over), and I'm hating it : it's slow on mobile, even worse on PC, where it regularly makes my whole OS hang requiring a reboot.

Scrolling back is atrociously slow, and it doesn't even seem to have a search feature !

I'd take XMPP alternatives like Conversations, Jitsi, Pidgin any day ! (And Element of course.)