This is debatable. I believe the current state of the art is that cattle are lower impact than cropping, so they can more safely be grazed on land where croppin

This is debatable. I believe the current state of the art is that cattle are lower impact than cropping, so they can more safely be grazed on land where cropping would damage the ecosystem. I agree that some land is too marginal for any kind of farming. You can graze stock on land that's going to be heavily degraded by their presence, and this is bad. You can also graze stock on land where trying to grow crops would cause damage, and this can be a better alternative.