Everyone seems to be surprised when I say we moved on to formula when Adam was about 4.5 months old. I would happily breastfeed him for much longer, but it seems it wasn't an option.
My view always was that we, women, have this ability to produce milk and feed our babies for a reason. If anyone chooses giving formula over their own milk, it's their choice, I don't judge. Some women have some trouble producing milk - that also happens. It's not up to anyone to judge a woman for her choice, as long as the baby is well fed and happy.