IRC’s UX never went away for the masses, people use IRC semantics all the time on Slack and Discord. The UX that never became mainstream once the internet was, is the same as it ever was: people by and large don’t value decentralization and don’t understand how to use it effectively. The closest it’s ever gotten was torrents, and even then most people didn’t branch out from TPB.
No, the only similarity Slack on Discord have is that they are "chat like" and have "chat rooms"/"channels".
But the whole UX around using them is very very different.
And that is what matters for the normal user.
Just the list of lacking default features is quite long, like: predictable display of formatting, emoji, pictures, file sharing, voice chat, nested conversations/threads, chat history,
different user roles, user avatars, etc.
And yes you can bolt all of this on top of IRC, but that doesn't matter. Defaults matter. At least for the common users UX.
And as long as the IRC standard doesn't include most of this points by default (especially chat history, avatars, etc.) it won't have another golden time.
Also no msg-commands as the default way to do things, programmers might like them, the common user doesn't.
