If we take "you need about 3x the time of a video to make a considered moderation decision" as a baseline, and trust the numbers from https://merchdope.com/youtube-stats/ as valid, we would need....
300 hours per minute * 1440 minutes per day * 3 moderator hours per day. Let's round that up to 1.3 million hours of daily reviewer time. Let us also assume we have super-human reviewers that can squeeze out 8 hours of solid reviewing a day. That means we need 160k - 170k reviewers. And then we need to account for illness and hols, so make that about a quarter of a million people, to keep up with the incoming and maybe make some inroads on what's been uploaded in the past.
That is actually less than what I expected, I thought the numbers would end up in the "low millions" (call it 3.14 million).
I'm imagining a world where the answer was "tough luck, you have to or you don't get to do business". Imagine a Facebook where due to the enforced human moderation you were only able to make a single post a day. That actually sounds like it might solve a lot of problems!