Companies exist to maximize some measure, and maximizing "social" isn't inherently a good thing. All the nonsense that happens on social media is the same as what happens in real life, but you can't monetize/optimize the real world in the same way.
Echo chambers - algorithms are optimized to show you more content related to your personal beliefs and interests. Then monetizes ads related based on your beliefs and interests.
Companies exist to maximize some measure, and maximizing "social" isn't inherently a good thing. All the nonsense that happens on social media is the same as what happens in real life, but you can't monetize/optimize the real world in the same way.