I don’t have anything against IRC, but to suggest it as an alternative to Discord shows such a fundamental lack of understanding of what Discord is good for that I’m kind of baffled. If you’re looking for self hosted alternatives then Matrix (especially with the latest video/voice chat rooms)is much closer to what Discord offers, but even that isn’t really a viable replacement for the core use case of Discord: voice chat while gaming + seamless video streaming of captured game footage with a UI so smooth that my 8 year old nephews figured it out on their own.
Yeah, I think there's just a disconnect in culture. Making IRC more viable towards those who like Discord etc. would fundamentally change and ruin it for many who like IRC. And vice versa. So IRC will never resurrect and be used by the masses again.