The article explains it in one case, an adult woman verified the account and then they posted a minor’s videos on it instead.
But the article also said that they only know about 30 cases in 5 years in the US. Which doesn’t sound like a huge amount to me personally (still too many obviously)
This is the US, minors posting themselves would also lead to arrests.
(And the actual platform with a reputation for minors selling their nudes would be Snapchat)