It's primarily being driven by a transition to low engagement media, such as social media and cable news, being the primary thought drivers of society. The average person was always pretty unwise, but they typically had to engage with their community in a productive way and would know an elder who was vaunted for being kind, fair, and intelligent, and who could be consulted when difficult situations were encountered. Now our society has been horrifically fractured into small atoms, so when people encounter confusing situations, they have a talking head (who's primary motivation is high viewership) explain something in a way that emotionally makes sense but doesn't actually encompass the complexity of a topic.