There have been reactionary waves before social media was even a thing. The progression of fascism and the rejection of rationality that comes with it are well understood, blaming it all on social media is a little cheap.

If you really want culprits, look at the right-wing populists that have been peddling anti-education and anti-science fearmongering for decades, and the patrons, who finance their campaigns and buy media after media to platform their propaganda.