They give up because they “fear” they can’t make enough milk. They need to ramp up production. The tiny babies don’t need as much. I suspect many give up because it’s a hassle.
I agree; is easy to give up. Breast feeding has to be VERY dedicated. Tons of hours sitting down with the baby. I couldn’t do much with my first son; too much constant pressure from my husband and my in laws; they would take the baby away from me all the time. For my second son, I was in control, and he was fed exclusively best milk for 9 months. The more you give, the more you produce, but you really have to commit; it’s very demanding. I estimate I needed around 8 hours a day.