Being vegan neither means no life will die nor the environment will be spared. On the contrary.
All life on the fields including small mammals, animals like hares, mice and such and all insects in a normal multi culture will be killed and replaced by monocultures that are not good for the soil and do not exist naturally. You can’t call yourself vegan while pretending to save lifes. You’re just trying to spare lives that you care about. Probably cows and pigs. No animals lives forever. We need to make sure these animals live a good life before they are consumed.
We’re not meant to eat plants. No doctor will tell you you can live well on a vegan diet without any supplements.