Bottle Feeding vs Breastfeeding Questions

Wife is thinking about switching to formula at 3 months because she's exhausted from exclusively nursing. I'm supportive obviously but I'm worried about judgment from her mom and her friends who are all 'breast is best' people. Financially we can handle it fine. Really just want her to not be miserable. Anyone else make this switch? How did you handle the comments from people? And does the baby do fine on formula? Just want to make sure we're making the right call for our family.