I think why Discord is such a haven to unstable guild admins/mods is because it sets such a low barrier-to-entry for a set of people to have power over something.
In the earlier years of the internet when someone would start a community they had to actually put their money and time into it, deploy a server or website, maintain it, and work through any surprises that come up. Those are things that would filter out many of the people that want quick fix of control over something, without ever contributing anything, and expect everything to be easy and free to them.
Since Discord is architected as such a silo, if you have an unstable admin that wants a final 'fvck you', they can just nuke it. Meanwhile with a website or other common services, it's usually possible for other admins/mods to have backups and be able to restore it elsewhere (you can't just 'reimport' contents of a Discord guild, comparatively).