Actually, almost zero soy is fed to cattle without oil, soy protein and soy lecithin being extracted for humans.
If you do it out of compassion for animals, go ahead, be vegan. But please don't try to get people to go vegan over stuff that a vegan diet has an equal if not bigger share in.
Mono crops fed to cattle and mono crops fed to people, economically, are one thing, one problem. A problem that must be addressed by addressing mono crops.
Don't turn the amazon fires into a vegan Reichstag fire. Just don't!