Whatme, you say "Bottle teats were originally copied from other mammals, not the human. Why do you think that was - that those other mammals all secretly bottlefed their young?"
Eh? Bottle teats were developed for the bottles they were originally designed to be attached to. They were not not not copied from 'other mammals' unless you can find another mammal who has mammary glands that look and act like old-style glass bottles.
Why would a product designer, faced with the technical problem of enabling a human baby get milk from a narrow-necked bottle, look to other mammals for inspiration?
These days, bottles are wider-necked, but they are still nothing like breasts, nothing like udders, nothing like gorillas' or dogs' or sheeps' or kangaroos' or horses' or rats breasts/mammary organs. All of whom have nipples that are different from each other and humans, as well.
But you probably have instantly decided you are now an expert on mammalian and veterinary anatomical issues, as well as rubber and plastic design, so I don't know why I bother, really :)
You also ask, "But lets go back a step...why do you think the human breast is different to all other mammals, then? For better feeding of human babies?"
Yep - primarily. I don't think many mothers would find their bf problems resolved if they used udders instead.
We do have fat in our breasts when we are not pregnant or lactating - there may well be other reasons for that.