I'm part of a community where people seemingly moved to the admin's personal Discord server thinking it'd be the site's official Discord server and the admin didn't stop them. The site still only points to IRC, but people are all on Discord anyway and IRC sort of got semi-forgotten by a whole bunch of people (until they need to use the IRC bots or the functionality of the site that is linked to IRC).

I left that Discord server because the active members always make their absolute best effort to move any and every conversation towards "minorities, trans people, and activists and why they should all go to hell right now" or similar. Not exactly a great place to be, right?

But back to the subject.

I'm not sure what to think about the IRC people you describe, OP. The admin that enforced Discord without any discussion of the subject is wrong for forcing the change, but there's a point where if you want to continue being a part of the community you have to move to where the community is, and doing otherwise would be a pride-based decision. If the entire community refused to go along with the admin and stayed on IRC instead of joining the Discord, then the admin in question could throw all the tantrums and threats and horseshit they wanted, but they'd have to move back to IRC sooner or later.

I'd honestly argue it's a 75/25 split with irc as the majority, 60/40 at worst
The primary issue is still the administrative discussions but that's something that needs to be ironed out separately from the platform. I get your main point, though