The thing is, when people try to argue that “killing” plants is also killing so I might as well just eat animals, apart from being an insane take as is imho, significantly fewer plants are harvested if you switch to a fully vegan diet. The net result is a lot fewer plants needed to sustain people vs. the oodles and oodles of plants and grains needed to feed cattle, pigs, whatever. There are these charts that show how much more efficient food intake really is if you cut out the middle-man - being animals - and just eat the plants they’d be fed instead.
People just try to discredit vegan whenever they can because of their own insecurities and cognitive dissonance. People who actively oppose veganism, that is