Humans are only walking digestive tracts. From an evolutionary perspective, all other organs originated from a primitive gut and have only one purpose: to serve it.
(credits to /u/susieq0044@sh.itjust.works who phrased it so well in this post, even though i had the thought already years ago)
But aren’t the gonads also not real in this analogy, since gonads evolved (skipping some steps) from single celled asexual reproduction and horizontal gene transfer. So aren’t you technically just your DNA?