I propose an alternative system, which would work better for YouTube than HN, because it is easier when more people use the service. When you create a new account, you have two options: either someone already on the network vouches for you, or you pay $20 (the more different methods of payment supported, the better). When your account is banned, if you paid the money it is lost; if someone vouched for you, their ability to vouch for people is limited somehow (e.g. normally you can only vouch for one person each month, and if someone you vouched for is banned, you lose this ability for 6 months).
To make the switch to new system easier, keep the legacy accounts (but without the ability to vouch for other people, unless someone vouches for them first, in which case they are no longer legacy accounts), and only apply this rule to accounts created in 2023 and later.
I think this is on balance a good and valuable thing about both sites. I was trying to show how your proposed solutions would, if applied here, make HN worse, as a way of illustrating why I don't think they're good solutions for YouTube.
(What made me think you were calling for pre-publication review was your "you can’t possibly expect us to vet all the content that we serve". Similarly, you objected to YouTube's approaches here as "reactive".)
For starters, anyone can just make infinite YouTube channels/accounts/etc. right now. There are no roadblocks, there is no vetting, nothing. All of their solutions are reactive and often too late.
I’m not even saying that a desirable or good solution is to vet creators. But for them to throw up their hands and say “we have no way of controlling the faucet“ is completely dishonest. We need to stop just letting that be something we all implicitly accept. They are making such insane piles of money off a system they fully control that is creating social issues, but we just let them abandon responsibility for it.