Most "farmland" in the Amazon is used for cattle grazing.

I think it's a little less direct than that, in this case. The Amazon Rainforest is a big source of cleaning CO2 out of the air (lots of trees). It's burning, which means our CO2 footprint matters even more than before. So, anything to reduce that is then good.

Also, a lot of farmland is used to grow feed for cattle and other livestock, and it's much less efficient than using the land to grow crops for people instead.