Back when my co-parent & I were navigating these decisions 6-10 years ago, we came across a study that really shaped our thinking: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4077166/. Basically, the researchers analyzed outcomes in families where the siblings were breastfeeding-discordant. The punchline: "Once we restrict analyses to siblings and incorporate within-family fixed effects, estimates of the association between breastfeeding and all but one indicator of child health and wellbeing dramatically decrease and fail to maintain statistical significance."
It's only a single study, but it takes a fairly unique approach to addressing the issues in observational research on the topic, and as such, we weighed it pretty heavily in our decision-making. It's also worth keeping in mind that parental happiness and mental health makes a difference, and breastfeeding was very challenging to my co-parent from that standpoint (although the details are another story).
YES! These points are tremendously overlooked. Breastfeeding was a major psychological issue for my partner for these reasons, as well as some others that might have been a bit personal or idiosyncratic. Either way, it's not AT ALL a zero-cost choice.