I still use a few niche IRC channels and run my own internal IRC network as a home automation message bus, so I'm a fan of IRC for its simplicity, but honestly: IRC really does need a modernization.
Things like image embeds, "markdown lite" formatting, and cross-device synchronization are now considered table stakes. There are always going to be some EFnet-type grognards who resist progress because reasons, but they should be ignored.
IRCv3 and Ergo support some of what's needed already (and in a backwards-compatible way!) but client support just isn't there yet, particularly on mobile.
> Things like [...] are now considered table stakes.
One other feature that's absolutely considered table stakes now is persistent server-side history, with the ability to edit and delete messages. Modern chat services are less like IRC, and more like a web forum with live updates.
(Yes, you can poorly emulate server-side history on IRC with a bouncer. That's not enough, and it's a pain for users to set up.)