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)
It’s all there so the DNA can make more DNA, if you’re serious about reducing humans to their most meaningless components.