A long time ago social media companies realized that spam, users getting scammed does does hurt engagement, so not worth devoting much money to fix it. YouTube has probably 1/2 billion users. A few thousands getting ripped off by scams is immaterial.

Algos are a scammer's best friend, cause all you have to do is stay one step ahead of the algo . Human moderators would nip this shit in the bud. Such videos would last minutes on Reddit but they last forever on youtube.