In addition, I’d reckon that at least part of this is due to the fact that IRC is somewhat centralized - to my knowledge (I only lived at the very tail end of the “popularity” of IRC) you couldn’t really be on one server and chat in a room that was on another server, right? Technically the protocol did have the capability for multiple servers to communicate (such as what would occur with netsplits), but you didn’t usually add someone’s server to the network as far as I understand (unless that is just a trend I missed out on).

[The rest of this probably deserves to be its own parent comment, but I’ll leave it as a reply here since it is partially relevant to the topic of IRC in this thread]

I’d think that at least systems like Mastodon, Matrix, and Lemmy have some resilience to this since they are very interoperable by their nature, but it’ll still need a ton of work done in order to get there.

The biggest problem is not the technological aspect of these applications / The Fediverse, but the onboarding and “human element” to them. I operate my own Matrix, Mastodon, and now Lemmy instances but out of the three I feel like Matrix was the only one where I was able to “see the world” so to speak without any extra steps. With Mastodon I had to subscribe to a relay in order to receive posts from other instances, and for Lemmy… well I’m still working that one out and trying to figure out how it works (I see new posts to the communities I’m subscribed to, and will see that it says there are three comments as an example… but they’re not visible?) - so I just don’t see how others are going to be able to avoid joining massive instances since you don’t have those issues there (or at least, to the same degree).