I've been messing around with a few other Discord alternatives lately, and one of them is Revolt. I'm really digging Revolt as it allows you to install custom themes, and it's also open source which is great so it's not tied down to a corporation. It doesn't have all the features that Discord has like forums, but I don't really think you need that feature in a chat client. (Sure Guilded has this too and their forums were much better than Discord's but still IMO not really needed...) I had created a Sonic server to test things out but since there's already a server I decided to delete it. Anyways, here's the link if you want to check it out.
https://revolt.chat/
https://revolt.chat/