Would you please enlighten me? I'm not aware of any issues about Discord that would warrant mass migrating communities over to a different platform. Also, I've never heard of Revolt.
Discord respects users' privacy a lot less and lately even considers honest emulation to be piracy.
Revolt is a small alternative. The things they disallow are purely because they legally cannot allow them, but they also aren't checking up on anyone whereas Discord nannies us.
Discord even makes changes that remove features from its users because it "doesn't think we can use them responsibly" such as locking anyone who isn't running a Community server out of permalinks.
Note that "Community" servers must also enable extremely draconian language filter bots that scan every message you write and might block them without the opinion or discretion of the actual Discord server's moderators. These bots might also prevent you from posting any image they deem inappropriate, which has frequently clipped perfectly SFW art just because it has too many skin tones in it.
This is before mentioning the requirement to join a "Community" Discord requires more than just a verified email now. They require people to also verify their phone number, which frankly, nobody on the internet should be asking for (that's creepy) under any circumstances, especially not the extremely flimsy non-concern over people using alts.
Revolt has stated upfront they have no interest in spying on people and their platform is designed with privacy in mind. They don't gate features behind agreeing to let someone with no attachment to your community make your rules for you and will really only step in if you're reported for doing something actually illegal. There isn't any contending with faulty content filter bots or having to submit the running of your community to people who are not even a part of it.
If you don't like the few rules that do exist on Revolt, they also allow people to host their own instances while still using their software as a user-friendly frontend, which keeps control of the community within the community, although it does require someone hosting it. I looked into the costs for hosting my own, and in spite of how expensive everything else has gotten, maintaining an IRC server is still pennies a month so long as you aren't noodling with image hosting.
Here's a link if you want to look around:
https://revolt.chat/
TL;DR: Revolt might be a reasonable alternative for communities which would like more freedom in how they express themselves (within reason) while also keeping control over how the community is run within the community, and making any final punitive actions on the part of individual users up to the discretion of that community's moderation team and nobody else's. (Unless you're reported for actually violating the law, then you might need to contend with the feds, but that's an edge case for most of us.)