the soybean meal is literally the byproduct of pressing soybeans for oil.
Byproduct does not equal waste product. Plastic is a byproduct, so is gasoline. Your conflating the ideas.
The use predates the creation of it. There had already been a use for it the moment it was made. It has never once been considered a waste product except in the style of argument you are making right now.
Yes, although I suspect we’d actually make less soy oil without the demand for feed. I’m honestly not even sure what it’s used for; most of the vegetable oils on sale where I live are different.
The corn case is pretty unambiguous. DDGS is a byproduct, white grease is probably a byproduct (maybe of pigs, which is “fun”), the rest looks purpose-made but isn’t relevant here.
I suspect we’d actually make less soy oil without the demand for feed.
i don’t know how we could prove this.