If it is any consolation, Mozilla (yes, that Mozilla!) moved over from irc to matrix back in 2020 if i recall correctly. So, i imagine that would represent a large-ish number of irc users, and many likely had been using irc for quite some time now. See: https://discourse.mozilla.org/t/synchronous-messaging-at-moz... and https://wiki.mozilla.org/IRC
If it is any consolation, Mozilla (yes, that Mozilla!) moved over from irc to matrix back in 2020 if i recall correctly. So, i imagine that would represent a large-ish number of irc users, and many likely had been using irc for quite some time now. See: https://discourse.mozilla.org/t/synchronous-messaging-at-moz... and https://wiki.mozilla.org/IRC