Another thing the twitter thread didn't mention, because it was presented as a universal "this is how stories are", and because it became so widespread in society, it actually acts as a barrier to creativity. Beginner writers feel like they must develop their stories and characters to conform to the monomyth, OR actively try to subvert it.

Because it's so pervasive, it's become a conceptual framework that blinkers beginner writers to other opportunities and story types.