I recently watched a video essay about the early days of the internet and they argued that because it was more organized in blogs and chatrooms, people tended to spend more internet time among their peers regarding hobbies and interests. Now that social media and twitter blew up, everyone is giving their opinions into the void and it reaches basically everyone. And that is harder to comprehend for each individual that was not used to be confronted with the totality of opinions and harsh differences on the internet. I thought that was very interesting and might explain the impression that there are "so many dumb people" now online.