Sorry, new chick mama.
There is something called failure to thrive. Actually, any species can have it. A newborn or newly hatched critter of any kind can have unseen problems, whether they are genetic or not, where they simply don't eat or drink correctly, slowly waste away, and seldom make it. It's sad, and unfortunate, and heartbreaking, but it's just something that happens. That sounds like the situation you had. There would have been nothing you could do to change things.
It's good that you came and asked, though, because sometimes new chicken owners don't know how to raise chicks properly, and they can learn what they were doing wrong in time to save everyone.