Maggie Mae Fish blasts into Campbell in a few of her videos and unfortunately I forget who did it but I saw a great feature length take down of thst asshole. Campbell used the literary studies equivalent of phrenology combined with a rigorous study of his own biases which he then, following the scientific method, made a bunch of shit up and called it a formula. It's just a 3 act structure but turned into something more complicated like Dan Harmon and his Story Circles. It's far from the be all and end all of how even western stories have operated including non modern classical literature.