Why don't you feed your baby?

I'm curious why women choose not to feed who can. Medically (no milk allergies, no inverted or not enough milk, etc.) studies say probably 95% of women can feed. If this is the case and it is the healthiest for baby, why don't more women do it? Just curious. (And yes, I do, I have a 4 month year old who is fed and I'm a full-time working mom). It is natural in my opinion. I know medical reasons hinder it. Yet, I think women give up too quickly. As for time, I am a college-educated working mother who has to pump so I know it can be done. If science shows it helps immunity and is best for the baby and you can physically do it, isn't that enough? I'm not trying to judge. I have friends who formula feed, just curious to WHY that decision would override all the benefits.