Do you have any source for that? In the ones I found, it’s more like 4/5 of the soy grown for human consumption is for oil, but human consumption is only 1/5 of the production.

See e.g. here https://ourworldindata.org/drivers-of-deforestation#is-our-appetite-for-soy-driving-deforestation-in-the-amazon, the oil production uses 13.2% of the global soy.