Right now I'm working with a dev from libera on a client that aims to replicate a lot of things experience-wise from newer chat services. Hoping that with that, smaller self-contained servers can become more of a norm~ But for now, your best bets for finding activity are probably Libera and a couple of the other larger networks.
From pseudonymous support requests I've received in our IRC channel and on GitHub, I know of more deployments that are either private (requiring authentication to connect) or on the darknet (we have specific support for running as a Tor onion service). So I think that's our niche right now: small communities who want full autonomy in moderation and control of their data. I've taken a lot of inspiration from Darius Kazemi's runyourown.social: <https://runyourown.social/>
Just so I could try to run an IRC server off of it.
Took about 3 hours to compile UnrealIRCD for it, but it worked.
From what i could see of the resource usage, it should have been fine with 128MB Ram.
The biggest issue I encountered was finding a distro old enough for a CPU without CMOV instructions that still had backported packages that were required to build the IRCD.