> Discord does have some user capture, but nothing like twitter's
replyMore importantly, Discord's communities are silo'ed, private by default, and administered and moderated by human beings with almost no oversight from Discord proper.
There is no equivalent on Twitter. On Reddit, going dark makes you subject to administrative subreddit takeover. But if someone runs a Discord community that they want to migrate to another platform, they could easily lock the entire server to posting and post a link to the alternative community. Done.
There's also really nothing to a community beyond its mods, its users, and maybe some bots. Reddit creates a record of EVERYTHING and in many ways those years of discussion are the sub more than the current users or mods alone. Discord is nothing like that, if you could get everyone on the same page a Discord clone would work just as well, and relatively seamlessly.
replytl;dr Discord has a moat, but it's not very wide or deep.
That's not true. Plenty of Discord communities have dozens of channels with long-running post histories, pictures, FAQ content, beginner guides; server roles and titles, permissions, custom emoji, stickers, etc.
replyMigrating all of that stuff to a new service (which may not even support it all) would be a huge pain.