it's silly that one would hope to even begin to approach the level of interconnected, interdependent, acausal complexity by simply starting with one problem, and then moving to the next, and the next. bodies and ecosystems happen all at once. evolution isn't a story of "A evolved to gain an advantage over B, and then B evolved to close that gap." it all happens at once and simultaneous with a million other things you will never understand.
there is no one cause for how a body is shaped. there is no one reason you cry. there is no one reason spiders weave their webs in the latesummer and no one reason a hand or a mouth exists. there is no one way you hurt or weep. it's all at once and even the twinkling of starlight bends us towards an inevitable yet improbable and unknowably dense unknowably braided form of a body.
a being that can think just a few thoughts at a time and that only conceives of processes as input-output can't begin to approach even the mind of its own body. much less that of how its hands crave to be held.