I used Hipp no.2 milk in a cup for DD3 once she weaned herself off the breast at just under a year old. I had found that cow's milk, which I had been putting into some of her home-made foods, was giving her eczema. So we cut out cow's milk and yogurt for a while. She was fine with cheese. She carried on drinking Hipp2 until she was five and a half, then one day she stopped drinking it, just as one day she had decided she didn't want to be breast fed any more.
DD2 was the same re the eczema and milk but not cheese.
We reckoned it was probably the cheese-making process that changed the proteins a bit (casein in particular) and made them digestible to them. I presume there is a similar difference in some powdered baby milks. They are not just dried cow's milk. There's a bit more processing than that, and added vitamins and minerals. So I wouldn't dismiss it out of hand.
DD1 also weaned herself off the breast at just under a year old and drank cow's milk with no problems.