As a counterpoint I’ll say that to the extent that the transfer of antibodies prevents or reduces infant illness, that is a win in the dimensions you describe on its own. A sick infant is both wildly impractical and hard to bond with.
For example, in this interventional cohort study with breastfeeding promotion [1], ”the percent of children having pneumonia and gastroenteritis declined 32.2% and 14.6%, respectively, after the intervention.”
[1] https://www.nec.navajo-nsn.gov/Portals/0/NN%20Research/Biolo...