Ask HN: What issues have kept YouTube from addressed thumbnail spoilers in recs?

Netiquette has long dictated that presenting late game or endgame content from newly-released media ("spoilers") is a major faux pas. Fans have often waited months, years, and even decades to experience a story as it was intended by its creators, and having that experience disrupted by inconsiderate or opportunistic posters can be very upsetting. The issue becomes more complex when the collision of unwanted information and viewer is enabled not by a malicious person, but a recommendation system. Presumably designed to present viewers with content that will keep them on the platform, such encounters can sour users on using an app or website altogether (if temporarily). I'd think platform owners would want to avoid that. Do they? If so, what causes the issue to continue plaguing users? Is it difficulty in setting apart "spoiler" media from "likely to engage" media? Or is there some counterintuitive phenomenon at play?

(Yes, this is about the new Final Fantasy video game.)

Even if just speculation, I'd love to hear your takes on it.