It's not a Discord replacement, full stop. Someone could make a Matrix client that was a Discord replacement, but no one has even attempted to do so as far as I know. Element (the reference client) was very clearly a Slack replacement. I know because I literally moved my small company to it from Slack. I think that Discord's continued enshittification could lead to someone making such a client either for Matrix or XMPP. That being said, making something like this isn't a small project and I wouldn't expect one soon if one comes at all.

Discord hating rant here: Discord is kind of weird as far as these sorts of services go tbh. Its "weirdness" is part of why I have always has a dislike of it (the bigger part of why is the jerky users and company, just like Telegram). It focuses heavily on VoIP and video screen sharing in a way that most chat services so not, but is also a heavily emoji/sticker/whatever filled chat service. It was clearly made for the shit talking gamer crowd and it honestly excels there. If it had stayed there in that niche, I'd think nothing of it. Then many FOSS projects and small companies then decided to use it in lieu of a proper support forum, probably because they were already were, or had previously been, shit talking gamers and used it all the time.