At the very least competition is needed.
YouTube is getting increasingly user-hostile with monetization with the huge increase in pre-roll and mid-roll ads, starting to lock resolutions above 1080p behind a paywall ( this was reported months ago but I've recently stumbled into my first two videos where 1080p60 and above was paywalled), and even getting aggressive on adblockers.
In the workspace Slack is very big and is very analogous to a supremely polished IRC. Discord outside of professional workspaces is similar, though a bit more detached.
To me, these are the mass market evolutions of IRC from back in the day.