Efnet split into #gbatemp and #gbatemp.net with the latter being more towards site style chat and !list being the order of the day for the former, though related discussions there too. Cheats also got their own channel and a few others, though they were more loose affiliates.
#gbatemp.net then left efnet some months later (years and years ago, several server switches even) onto a dedicated server (ability to save nicks, register things and more generally being viewed as useful) and exists to this day (
https://gbatemp.net/dynamic/gbatemp-net-irc-server.57/ ). Occasionally another fad protocol will pop up, siphon off a few regulars/members for a while and eventually get knocked down (right now it is the turn of Discord, which is looking increasingly wobbly for a lot of things) but IRC weathers it all, almost as though having open protocols, open clients and the ability to run your own servers is a good thing.
As far as efnet goes then something still exists there though is protected.