It takes time to absorb nuance, especially if it's nuance that challenges your current beliefs.

It takes time to absorb nuance -- to see that it's not black and white but actually a shade of gray.

It takes time to be convinced by information that goes against your current beliefs, in proportion to how different they are.

To appreciate the shades of gray in a topic takes time and study, otherwise you get posterized extremities.

If you have a limited amount of time, you'll get the superficial take that is cast into sharper relief than it should be.

"That looks superficially like the thing that is opposite what I believe, which I know to be wrongheaded and I can thus reject out of hand"

In an increasing cacophony of signals, there's less time to attend carefully to any particular input.

This means that all else equal, we'll see increasingly self-strengthening beliefs.