Earlier quoted context omitted.
Rarely is human genetics this simple. For ages geneticists thought large swaths of the human genome were "junk" and over time more and more of it has been proven to have a purpose or function, it just wasn't readily apparent for various reasons. Think of the human genome as sort of the ultimate dependency hell...
Nature does not refactor. There's the laryngeal nerve somewhere in the neck of mammals that has to go around a blood vessel. On Giraffes, this runs all the way down the neck, around said blood vessel, than back up, all that just to connect two places in the upper neck that are inches apart. Evolution writes the ultimate spaghetti code. More info: https://berto-meister.blogspot.com/2011/08/unintelligent-des...
If nature doesn't refactor, then why are there so many crabs?