Who benefits from attacks on the notion of truth? Liars.
Who benefits from attacks on rationality? The confused but proud.
As I have said many times, it is astonishing that so many people have fallen under the thrall of bad ideas, particularly in the midst of economic and political plenty, made possible only by the long term application of the ideas they oppose.
Sociopsychologically, this can only be explained by the sociopathology fed by the fact that only useless, emotionally damaged or limited people choose to pursue study in the Humanities, by and large. They are the ones nobody liked, or who always felt inferior for some reason or other. They get their revenge by inflicting damaging ideas on the world as a whole.
They may yet submerge us all in a flood of fire or water. I personally cannot fathom how so much ugliness can be finally admitted by people who need it.