To quote myself "Its sole purpose is to prolong engagement...", so we are on the same page here. But there is downside to this, it often hijacks your dopamine system and can be addicting. It doesn't only do that, occasionally you get content that you disagree with and interact with because of it. That also gives you pleasure to tell someone that they are stupid. This is why there is a such disproportionally high reach of e.g. flat earther content. People engage with the content to tell them that they are stupid all the time, but sometimes it sucks someone in to their rabbit hole. It is a fairly benign example... so what about anti-vaxxers or QAnon? These people are enjoying themselves to the point that they delusions take hold. And I blame the maximization of engagement.