As much as I like XMPP it is not a suitable Discord alternative at all.

Discord has dozens of permissions that can be tied to user specific roles (or users directly) and that allow you as a space (bc I refuse to call them servers) owner to hand craft which role / user can do what. On Matrix there are a lot fewer permissions than on Discord but it has the basics. On arguably the most advanced XMPP apps Cheogram & Monocles (if you know a more advanced one I’d love to test it) you can allow/deny anyone to edit the topic of a room/channel/group and allow/deny anyone to invite others.

Also the reason why i.e. no lemmy community links their XMPP group but those who do have spaces operate them via Matrix is because it offers invite links, or even spaces to begin with. All it can do is single separated groups.

Atm Commet (which feature & ui wise I would say comes closest to Discord alongside Cinny and Element/Schildi) features Text rooms, voice rooms, media rooms and calendar rooms. Whilst Monocles and Cheogram (who are both forked from Conversations and one is maybe forked from the other by the looks of it - idk who was first) both have experimental Threads support, not to mention that you can cross sign Matrix sessions to sync which messages you can read whilst on XMPP you either manually export and import a backup or just live with the fact that you cannot see previous messages. Oh, also on Matrix based messengers you can usually see which device sessions have access to your account and you can throw them out. I haven’t seen something similar on XMPP messengers.

Now there are some cool features that “Conversations” based clients offer like little RTC web apps (only on the forks) and the possibility to run your traffic via Tor.

And the protocol XMPP could certainly do much more than even Monocles/Cheogram offer atm but Matrix clients just are much further ahead in having their protocol’s features implemented (which yeah, probably comes from the fact that Armdocs, the German and French military and some regional governments have poured some money into Matrix (& Element and the company behind it).

But even with these (sometimes dubious) links Matrix is the more full fledged experience that is open source and self hostable. And on the centralization part I am pretty certain most XMPP users use either conversations.im or monocles.eu and the amount of Matrix providers is much broader than the amount of XMPP providers too.

Now to make one thing clear: I don’t want to hate XMPP. I like it and it deserves better. But realistically it is not there yet. Mayyybe if you really wanted you could replace WhatsApp, Telegram or Signal with it (tho I am not sure if I’d recommend replacing Signal with an XMPP based messenger atm) but to replace Discord they’d need to catch up to Matrix first in feature adaptation and userbase.