IRCCloud implements it but servers don't, and IRCCloud feels kind of dead development wise. And it doesn't really solve the problems that Discord solves, for example.
The dream of instant messaging being built on top of open protocols, just like email, doesn't feel terribly far out of reach but it also doesn't feel like we're making progress towards it and the efforts spent on keeping IRC alive feel, at least to me, kind of futile compared to say, efforts spent on Matrix.
I don't think it's crazy to leave IRC behind, and most people who mourn it will either do so out of nostalgia, or because of the loss of an open protocol. I'd rather centralize on something that has a future though.