The short answer is 'We like our bubbles.'  The solution might be to re-institute the Fairness Doctrine. 
(worth a read)

93% of Fox's audience votes Republican
MSNBC's audience is 95% Democratic
New York Times is now 91% comprised of Democrats
New Yorker 91% comprised of Democrats

https://taibbi.substack.com/p/be-it-resolved-dont-trust-mainstream