Babies don't suction milk out of the breast, rather they take the nipple and areola into the mouth and squeeze it between the tongue and palate to express milk.
Milk from bottles is by auction and it's usually easier than breastfeeding.
(Learned this from a lactation consultant for my daughter)
Having read more about the mechanism of suckling, it seems even more clearly important to the development of the jaw, because the baby uses their tongue to draw the milk out of the nipple, which requires applying pressure with the tongue from front to back against the palate. Bottle feeding requires simple general suction.
Milk from bottles is by auction and it's usually easier than breastfeeding.
(Learned this from a lactation consultant for my daughter)