The most important benefit which comes to mind is this: https://www.sciencenews.org/blog/growth-curve/backwash-nursing-babies-may-trigger-infection-fighters When your baby latches directly, baby saliva gets sucked back into your breast and your body will create customised immune factors which will then again be delivered to baby in breast milk. This is lost when pumping as there is no contact between your breast and your baby's mouth. Also, when breastmilk is stored and fed to your baby, some antioxidants are lost, especially when milk is heated. It is still more nutritious than formula.
the fact that the mum's body functions like an satellite immunity center for the baby is amazing, the human body is miraculous
thanks