We have always been in a post-truth era because our interpretation of truth can only ever be subjective. Today the difference is that Trump doesn’t pretend to be objective. As a narcissist, it is impossible for him to be anyone other than who he is. I’d wager he believes his own stories, no matter what facts might say.
There are some instances where objectification is entirely appropriate and needed. For a short while–for example–a baby cannot walk, and cannot feed itself. They have no agency, no power to decide on where they go or what they do. As parents or caregivers we take on this agency. We are literally a baby’s arms and legs… we dress them, we feed them, we pick them up and put them down.