I assume I don't have to try too hard to convince someone on this forum how easy photo/video verification is to bypass. Look at Australia, it's happening en masse right now.
Most age verification systems guard against children pretending to be adults. If we're talking about social media, this is a fairly low stakes thing, and false positives aren't too critical - sure, a teen will bypass the Instagram age-check and use Instagram, big deal.
Here you're trying to guard against the exact opposite - adults pretending to be children. Not only are the stakes way higher as there's no legitimate reasons to try and bypass the system, you also don't have access to the only reliable method - government ID checks.
Edit: I can concede the point about Schlep, as what he does is dangerous and I could see someone "follow in his footsteps" and ge thurt. However you have to keep in mind that he's never the first to talk to these people -- there's so many of them that he's literally had dozens of them approach him. I was mainly thinking of Ruben Sim, who compiled a large database of NSFW accounts without any real world interaction, and was banned and sued for it.