I’ve eaten apples, and I’ve eaten pomegranates, and a bunch of other fruits, and none of them has ever imparted any sort of metaphysical knowledge on me. Clearly, the Forbidden Fruit wasn’t an apple or a pomegranate or whatever; it was a Tree-of-Knowledge-Fruit. That species is now presumably extinct, or (at best) extant only in an extremely small and inaccessible-to-humans range.