Exactly @HostaCentral
I also find it interesting nobody talks as much about the benefits of formula, which very much exist. Being able to share feeds, and get more rest. Knowing how much your baby is drinking (avoiding rehospitalisation for failure to thrive), baby not needing vitamin D drops, guaranteed to be able to give them enough calories. And for many mums, better mental health. More info below though on the idea that breastfeeding has longterm benefits for babies (clue, it doesn't!)
When looking at the WHO recommendations, it's important to remember that they are thinking about public health policy for the entire world. Access to clean water changes everything, and in the developed world the benefits of breastfeeding are marginal at best.
‘Breast is best’ is pretty much woo (except for premature babies.) The difference in outcomes for breastfeeding versus formula feeding is trivial to nonexistent once you control for socioeconomic status - the reality is that wealthier and more privileged families are more likely to breastfeed.
Sibling study used to control for socioeconomic status:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4077166/
The real benefits to breastfeeding are a slightly decreased risk of GI illnesses, respiratory illnesses, and a slightly decreased risk of cancer (for the mom, not the baby). But that doesn't make breastfeeding the right choice for everyone, and it doesn't make breastfeeding vastly superior to formula in the way that many say it is.
https://fivethirtyeight.com/features/everybody-calm-down-about-breastfeeding/
On a population level, when you look at hundreds of thousands of babies, breast milk results in fewer upper respiratory infections and fewer gastrointestinal infections. So, yes, health authorities promote breastfeeding and formula companies are legally responsible for writing "breast milk is better" on their can. In theory, if hundreds of thousands of mothers BF instead of FF that's millions of dollars in saved health care costs. (But note that these proposed health care savings have only ever been modeled and never validated in the real world. Meaning they probably don't happen.)
But on an individual baby level, there's really no appreciable differences (see the sibling study and the probit study).
http://www.slate.com/articles/health_and_science/medical_examiner/2006/03/tales_from_the_nursery.html
https://sciencebasedmedicine.org/questioning-the-evidence-for-breastfeeding/
https://expectingscience.com/2015/11/02/breastfeeding-benefits-the-real-the-imagined-and-the-exaggerated/
This is a very long report. You would need to read the whole thing including the issues with the studies used: https://archive.ahrq.gov/downloads/pub/evidence/pdf/brfout/brfout.pdf
And also, these benefits (slight reduction in infections on a population level) are strictly short term. None of the claims about long term impacts of breastfeeding are supported by evidence. There are no proven links between breastfeeding and IQ, obesity, behavior problems, parental attachment, food allergies, ADHD, or any other of the long-term health indicators often put forward as reasons for referring to breast milk as “liquid gold.” Sibling studies have produced “results suggest[ing] that much of the beneficial long-term effects typically attributed to breastfeeding, per se, may primarily be due to selection pressures into infant feeding practices along key demographic characteristics such as race and socioeconomic status.” https://www.ncbi.nlm.nih.gov/pubmed/24698713
At a year old, there is precisely zero difference between a breastfed child and a formula fed child. Breastfeeding is not going to set your child up for a lifetime of success, and formula feeding does not create lifelong issues.
It's also important to keep in mind that infant feeding is not just about which liquid your baby is ingesting (breastmilk or formula). There are also lifestyle impacts that vastly outweigh any factors about the milk itself.