They are, they’re trying, they’re pushing other platforms constantly. Kurzgesagt already does, heavily.
But are users switching? Nope.
They hardly even know they exist.
Sometimes I even see such a comment on YouTube, a user questioning YouTube; yet they didn’t even watch the video long enough to see the creator promoting an alternative platform.
They’ve already scrolled to the next video, algorithmically fed to them.
YouTube has an iron grip on YT users, and they know it. Even if ALL creators band together, IMO there’s basically nothing the creators can do.