But animal feed also contains soy oil, so even allowing for part of soybean production being used for human consumption, there remains a significant part of soy effectively produced for the benefit of livestock. Furthermore, animal feed production incentivizes the cultivation of soy. If there was no animal feed incentive, there would not be a need to expand soy cultivation into virgin land.
Which bring us to animal feed causing increased land usage (which could be reforested if nothing else), methane emissions, and waste production connected with raising livestock.