Most of the polarization happens in popular and commercial websites.
Those systematically draw a profile using algorithms with the purpose of leading you the consumer to buy products or services.
Repetitiveness is the key. You see repeated things all the time, until you think you really need them. It is how human brain is made.
Since marketing including deceptive marketing is legal, this will only get worse in the future.
I see no magic solution with existing capitalistic regimes and financial system.