> but IRC wasn’t
No, sorry, I was there. That's the key thing people need to remember about the Old Internet.
Some of IRC was extremely racist and sexist. Almost all of the rest was "regular" racist and sexist. It was pretty closely related to 4chan culture (under-moderated by outside forces that had little power to force any particular standards upon the moderators). The magic of the medium was that since everything was text, nobody knew you were the butt of the joke and you could pretend you weren't.
But go mask-off and admit you were a woman or a minority, and oh boy. Good luck with that. Good thing it's easy to change your handle, right?
There's a reason anonymity as a virtue grew in that space: it protected people from those who hadn't left their IRL baggage behind by letting people pretend to be the "default" (which was almost always white men).
We made a mistake believing the online space wasn't the real world. It was. It was just the real world where you could pretend to be something else. That was good at the time; it let more people participate by donning masks. But we should aim for better.