That goes hand in hand with the echo chamber social media creates. People end up surrounded by other voices who believe what they believe and whip each other up into a frenzy. Add in well-funded groups and organisations that would benefit from whatever belief they want to push, and technology kicks in to amplify the division.
Truth doesn't matter anymore. Non-believers are seen as naive, deluded, blind to the obvious, stupid, the enemy etc etc. This fractured world we're currently living in is a direct result of this. It's not hard to pick someone down a rabbit hole. They are so convinced they know the truth that is being hidden by the elites, dark forces, MSM etc that they ridicule anyone who questions them. They can be quite aggressive in their attack because they've been whipped into a frenzy.
Here's a classic example of the rabbit hole. The people interviewed here are so convinced of what is happening that if it doesn't turn out like they expect, someone has cheated. They are even prepared to die for their cause and make sure others die as well. It's *smile* madness.