Soybeans have probably a worse impact on the environment than beef. Most of the deforestation in SA in the past couple of decades was for soybean farms.
It's the meat industry that is primarily driving deforestation, both directly for pasture, and indirectly for animal feed.
Does soybean production as a whole, in SA, is worse than beef production as a whole in SA?
Maybe.
Does soybean production for direct human consumption is worse than beef production for direct human consumption?
Not. Even. Close.
https://www.wri.org/insights/truth-about-low-emissions-beef
Basically you're average meat-eater is indirectly eating more soy than someone having scrambled tofu everyday