I gather that the Vegan argument against killing to eat is that animals should not suffer for our benefit.
But plants seemingly suffer, too, when molested and killed — they are just not in a capacity to look at us with sorrowful eyes. Indeed, the nature of plants have gone under the radar of science, partly because we have not had developed techniques to research them. That we have, for a large part, now.
And they apparently tell us, that plants communicate, that they react on various kinds of handling, and they actively sometimes try to protect themselves.