If I can suggest a different perspective: that lack of scrollback is what makes IRC special. When you join a channel, instead of just scrolling back to whatev

If I can suggest a different perspective: that lack of scrollback is what makes IRC special. When you join a channel, instead of just scrolling back to whatever topic you care about and joining the subthread, you get caught up on what you missed by engaging with the channel instead. It drives community this way.