Iavor Diatchki
Hello,
I am not a heavy IRC user, but I'd say it makes most sense to just use Libera. It is essentially the same people that were running free-node running pretty much the exact same service, and I believe they are trying to make it extra easy to just switch, so this should be the least effort transition.
I believe IRC has served the GHC community quite well so far, and there is a reddit post by Ed Kmett that the normal Haskell channels have already been transitioned over, so I think it makes sense for GHC to stick with the rest of the Haskell community.
The problem is that, in order to grow (or even merely not to shrink), the community also needs to adapt to the preferences of younger users. The fact of the matter is the younger users tend to be, at best, unfamiliar with IRC. In the worst case, the need to leave a browser/sign up for a new account means that they simply won't participate. Of the new contributors I have had approach me in the past year, less than half have had any familiarity with IRC. Matrix has the advantage of being accessible to "web-native" community members while being open enough to (at least in principle) allow community members who are accustomed to IRC to continue to participate via a bridge. Cheers, - Ben