> These fortifications come from [...]

Many baby's brewage or powder are also skimmed and re-enriched with fortifiants AWA most cereals and salts. Caw milk has more Calcium and Phosphorus but Soy milk gets more Iron, Magnesium, Fibers and Polyunsaturated Fats. You easily get P from lentils and Ca from green vegetables, without fortifiant.

Milk protein efficiency is 25% [0], this means with 1kg of soy you either get 380g of soy protein or 95g of whey. Accounting for a bio-disponibility of 0.95 the ratio is still 1/3.8! This is so inefficient that a lot is wasted in US and Brazils :

> 97% of U.S. soybean meal goes to feed livestock and poultry. [1]

0: https://ourworldindata.org/grapher/protein-efficiency-of-mea...

1: https://soygrowers.com/key-issues-initiatives/key-issues/oth...