I don’t see how it’s is a statistical fact. There’s nothing I’ve seen on YouTube that compares even slightly to a high quality movie or TV series (unless it’s an unauthorised copy of a movie or TV series…).
anyway, as for the statistics, for the case of YouTube since there are is no forced directive to which all videos must follow (creatively), you can treat all videos as random attempts. then it's just stats to show that such a distribution will have outliers that match or exceed in subjective quality the gate kept works (traditional tvs or literature).
If you want to argue that art is created by pure randomness that’s fine, but I don’t think we’re going to come to an agreement.