It’s true.
Soy is one of the highest plant sources of protein but that's about all it's got going for it, especially in its unfermented form.
Because soy is such a high source of protein (at 35% of the raw bean), it has made the global factory farming of livestock for cheap meat a possibility. It is now an everyday staple agricultural feeds for intensive chicken, beef, dairy, pig and fish farming. And soy increases the protein content of processed meat products.