Certainly the number of moves to Libera is high enough that in practice the Freenode community/userbase is more or less also on Libera (turns out IRC clients can connect to multiple networks easily). So if you want the old community it's there; if you happen to want to target a different community anyway (and perhaps you were experimenting with these options already), Discord and Slack and so forth are there.
It’s not a lot different from irc if you are using it for chatting in channels.
Edit: okay I get it.
All before you get into the technical differences in applications and protocols - good and bad.
...and it has less users than channels.
Discord should have a "lobby" server where every small group could have a (private, invite only by default) channel. After they have enough people they could upgrade that to a full server.
But it's too late now and I already have 50 Discord servers on my client, of those maybe 4-5 have over 50 people on them. The rest have more channels than members.
Though, one can also migrate to Matrix.
It's less about the protocol itself and more about the community/culture, I trust tech savvy people more to care about privacy than profit-driven platforms like Discord.
It appeals primarily to a subset of Web 1.0 enthusiasts.
https://www.wsj.com/articles/fbi-sting-using-anom-platform-l...
They're all fully searchable and indexed on a private psql instance.
However it's not unreasonable to assume that most three-letter agencies (and perhaps some companies) will simply have bots silently sitting in most large public channels (if those channels don't have public logs anyway).