I was big fan of xmpp until I have to admin our company internal server (can ignore all the s2s stuff).
I was surprised how poor is a basic protocol description. Any functionality expecting from common messenger is provided by some protocol extension (XEP).
Many of them never have passed "draft stage" touched last time 15y ago. It's not easy to find server and client supporting some pretty list of XEPs. We are using pidgin client (Linux+Win support) and I'm pretty tired answering questions like "I want feature XXX I can use on my Miranda". My typical answer is "sorry, Pidgin just cannot do it". Or "this is unaccepted protocol extension (XEP) and every client implements it different and uncompatible version."

Yes. If you want to send simple text message, it's fine.

But it's mostly abandonware.