I pumped for my son because he wouldnt latch, and my was i a cow! I had to pump every 30min I was so full. I fed on demand and he slept great! He is 7 now and not obese..quite the twig actually, he should eat more lol.
The breastmilk babies Ive had also were happy and slept 3hrs at a time for me and im told they sleep through the night. I can only go off of my experiences and in my experience, feeding on demand led to happier babies who slept great
To each there own.