Reading (briefly) ONLY they sources you have listed:

1. I am in no way going to argue that socio-economic factors impact whether a mother breastfeeds. This is not in contention in any way. The question is which is best for a newly born child breastfeeding or formula.
2. Intelligence was also not something I have mentioned and the science between intelligence and breastfeeding is settled and again not what we are discussing
3. Actually wraps this conversation up "Although the benefits of breastfeeding in reducing [morbidity](https://www.sciencedirect.com/topics/medicine-and-dentistry/morbidity) and mortality from [gastrointestinal and respiratory infections](https://www.sciencedirect.com/topics/medicine-and-dentistry/gastrointestinal-infection), [sudden infant death syndrome](https://www.sciencedirect.com/topics/medicine-and-dentistry/sudden-infant-death-syndrome), and (in preterm infants) [necrotizing enterocolitis](https://www.sciencedirect.com/topics/medicine-and-dentistry/necrotizing-enterocolitis) are well-established, long-term health effects are more controversial."

Research now is being focused on long term affects such as allergies. Again I think you need to more in depth reading or have a chat with a pediatrician if you are honestly interested.

I am also not trying to be argumentative without purpose here, but what you are saying just isn't factually true and I worry that a new mother may read this and take it on face value.