Babies that are on a bottle feeding aren't stronger? aren't healthier? im bottle feeding should i be worry or feel guilty?

Relative issue: Breast fed infants, even if breast fed for a few weeks, seem to have better life outcomes than those started on the bottle initially.There are also living immune factors that breast milk has that reduce some of babies illnesses.That said, there has been tremendous improvements in formulas in the past 3 decades and babies thrive. I think mom's have to do whatever it takes and not accept guilt for it.