It's not a full replacement for Discord, but it's working towards that. If you just want a basic server for yourself and friends with emotes and voice chats, Revolt works. If you want polls, events, threads, forums, etc., it can't replace your setup. I think the goal is to be a full Discord replacement in the future, but it's still a work in progress (such is often the case with FOSS software maintained by hobbyists).