Breastfeeding is hard. A lot of moms try and have a hard time getting through “the wall” of the first week or two. Taking nothing away from them, it’s very hard, more so if the difficulty wasn’t anticipated ahead of time.

I’ve watched my wife do it three times, with the 3rd time being right now with a 6 week old.

Second this. It is amazingly difficult. So many factors at play, all while sleep deprived, thirsty, on top of regular life.

When working well, though it is miraculous.

The U.S. doesn't have guaranteed maternity leave. Even 4 months is considered generous. Many people will pump breast milk during the day, and deliver it to the baby in a bottle.

In this specific case, breastfeeding twins is harder than breastfeeding single kid. Booby factory might be overworked due to increased demand :)

It is relatively common to bottle feed here, either with pumped breast milk or formula.

It's a mix, some do some don't. About 30 years ago it was not common at all, but there has been a huge reversal.

The messaging right now is that breastfeeding is better, but be careful not to oversell it so that you don't make those who can't feel bad.

Very common, although breastfeeding is also common. In our case, we primarily breastfeed but supplement with formula.

Some thirty years ago, as my parents would tell it, people would primarily just use formula.

Yep. Around the 70's or 80's, there was a reversal of the consensus of whether formula is just a good as breastfeeding. Personally, I think even pumped breastmilk isn't as good either because it lacks the psychological effect of skin-to-skin contact, the exchange of smells, and the immediacy of breastfeeding. I can't imagine leaving a 1-3 month old screaming every time its hungry while the parent spends 10 minutes gently thawing some milk. What if he develops some sense that food and security is scarce forever suffers some emotional damage?

Why? Do you think something's wrong with that?

If you believe the consensus of medical professionals, then yes there is. In my country, Infant formula comes with a government-mandated warning on the tin recommending you not to use it. Maternity wards won't give it to newborns unless there's a medical need, and if the mother can't produce enough milk, they work hard to ensure that she can. That's the "appeal to authority" reason. How wrong it is, and even how sure we are of that, I have no idea.

Studies have found correlations between breastfeeding and later outcomes. But those studies have a bias. For example, mothers who graduated college are more likely to breastfeed, and their children are more likely to go to college.

The only way to factor out the biases completely is with a twin study: same mother, same environment. That's what they did with the "Twins Early Development Study." This study found no correlation between breastfeeding and IQ after the age of 2.

There’s a good study out there that used parents that couldn’t breastfeed. Some used donated milk and the other group used formula. There was a correlation for IQ, though it was pretty small.

did that study also look at health? my understanding is that the point of breastfeeding is a better immune system

In the PROBIT trial, "13 percent of the children of mothers in the group that wasn’t encouraged to breastfeed had at least one diarrhea episode, versus only 9 percent of those whose mothers were encouraged. The rate of rashes and eczema was also lower in the group whose mothers were encouraged to breastfeed: 3 percent versus 6 percent."

"In this particular study, we cannot reject the possibility that breastfeeding could matter in either direction—that it could decrease or increase respiratory infections. What we can say is that the data doesn’t support the claim of a reduction in respiratory infections as a result of breastfeeding."

"These researchers have continued to follow the children in the trial through the age of seven. They find no evidence of any long-term health impacts: no change in allergies or asthma, cavities, height, blood pressure, weight, or indicators for being overweight or obese."

Quotes from Crib sheet by Emily Oster. On the other hand, one compelling reason to breastfeed is for the mother, not the child. Breastfeeding lowers risk of breast cancer.

To me, it would take a mountain of effort to force myself to believe that breastfeeding is not better than formula.

It does not take a lot of effort: just look at a class of children at any grade in any country.

Can you accurately predict which ones in the class were breastfed versus formula fed given all information (excluding their feeding)?

If you ask teachers the answer is you cannot.