Strong opinions drive interaction. Driving polarization is is monetarily beneficial.

A moderate viewpoint gets glossed over because it doesn’t stand out. It won’t drive views, revenue, interaction, responses, etc. It’s the extreme claims and views that bubble to the top of media and social media via algorithms designed to elicit response or interactivity.

Even if moderate views exist, they get suppressed. Then people also want response, so they skew what might otherwise be moderate opinions to be more aggressively polar in order to get that response. The polarization is mutually self-reinforcing as a result of existing algorithms.

It would take active algorithm design seeking to deemphasize extremes to attain anything else. This would naturally decrease user interaction (and thus $), so it’s unlikely.