The "everybody is stupid except for me" hypothesis (which is more accurately the "everybody who disagrees with me is stupid" hypothesis) has been around for ever. Conceited people have been espousing this since we first learned language. The basis of it is a failure to understand that your opinions are in fact opinions, and instead believe that they are established/unassailable/scientific... fact.
The only thing that's made it appear worse than before is an increase in political polarization. That has made people less likely to believe that people with differing opinions are simply people with different views to them, and more likely to believe that people with differing opinions are simply wrong/stupid/malevolent. For every person out there wondering why people are so stupid, there are other people making equally valid observations about them.
The only thing that's made it appear worse than before is an increase in political polarization. That has made people less likely to believe that people with differing opinions are simply people with different views to them, and more likely to believe that people with differing opinions are simply wrong/stupid/malevolent. For every person out there wondering why people are so stupid, there are other people making equally valid observations about them.