Jitsi supports screen sharing over XMPP, so obviously this is possible. I believe Empathy does this as well. No single program has all the features, however. There are advantages to Kopete, integration being on of several. I really wish Kopete included remote screen sharing over XMPP. I searched and saw no existing request for this aside from one for Skype protocol specifically. Reproducible: Always
Dear user, unfortunately Kopete is no longer maintained. Please migrate to another solution, e.g. for Jabber a possibility is Kaidan, for Matrix a candidate is NeoChat.