Not remotely.

IRC is distributed and federated. Not only are there countless networks, each network has countless servers, and each group of servers that are up and can see each other can operate on their own, all the way down to a single server, or up to any subset up to all.

When a peering connection goes down and the network splits, maybe some people in the group disappear, or maybe from your point of view everyone else disappears.

Maybe the remaining subset of other users is already good enough because it's enough to continue what you were tallking about and who you were talking with, or if not, you have the option to just try some other servers until you find where everyone alse is. Were "server" is an actual seperate instance of the server software operated by an independant person, hosted on whatever kind of hardware or vm they set up, connected to whatever network they are on, not what Discord calls a "server".

Even if the entire group of say freenode servers goes down somehow (even though that's not really possible) there is still undernet and 400 other nets. Even without prior coordination it would be essentially trivial for the users to all just go looking for, or create on the spot, the same channel on some other net, and basically everyone finds each other again almost effortlessly. And that's if something unbelievable actually happens, let alone the normal minor breaks that actually happen once in a while.

This is entirely different from being wholly at the mercy of the single entity Discord.