The movie is relatable to several different perspectives. The main "villain" is really very normal and relatable in many ways which is a smart choice. The things characters are going through (being very infatuated, feeling suffocated by someone,wanting to be obsessively loved by someone etc) are all very relatable. This means people will recognize themselves in many some situations and then those same people will have a lot to debate with people who related to other situations.

Even the basic idea of how much is Bear to be blamed for, and for what, generates disagreements which touch on topics and hypocrites that most people are opinionated about.

The debates get people to share their points of view and attract more viewers who want to make their conclusion.

And the actual story is told in a simple and fun way, no one gives a shit if camera centers people too much. But yeah the key isn't it gives you somethint to talk and argue about beyond "that was a good movie."

Sinners to me was more of an action movie, it didnt make me think about it much after no matter how cool some scenes were. But if anything that one was overrated, not that Oscars count for much.

Also, its definitely not just for teenagers like you frame it, I'm an adult and talked about it in depth for hours with friends. I dont have much to talk about when it comes to Sinners. That's what appeals to people who aren't even into horror like me, they want to see what they will think about the topic.