Is this something that should be a limit to scale then? If you instead ran a petrol station that grew so large that you couldn't economically hire enough people to safely and fairly service all your patrons, you've reached a natural limit of the scale of the business. I think it's fair to say that if they're failing to moderate the platform in a way that doesn't harm it's users fairly regularly then they've reached a limit to their scale. Remembering as well that a lot of their users are clients, making business transactions with YouTube, not just users watching content.