I'm not even vegan lol, strongly considering it though and you're helping :)

Since taxa is the same for you no matter the level, hey, why do you eat your brothers fungi, herbs and tree babies? Are you some kind of a cannibal?

Do you not know what cannibal means? It's not a general purpose insult for people with dietary choices you don't like, it actually has a definition and it's not an animal eating plants and fungi. If you're going to resort to name calling, at least make the effort to come up with a clever zinger or something.

But if you care about plant lives so much, you should in fact be vegan. Feeding animals to kill and eat requires 10x more plants than just eating the plants yourself. It would also dramatically reduce the amount of farmland required to support humanity, meaning literally more space on the planet for more natural forests and grasslands that contribute to the ecosystem.

Finally, you thought I was talking about chimps or something and not humans? You don't think prehistoric humans when they first became their own species, before the idea of a society or even a tribe developed, lived in social structures similar to the other very closely related ape species that we literally split off from? Even something like a hunter gatherer tribe is still a fairly complex society that needed time to develop. What were we doing before that? We were all chilling in the savannah with absolutely no conflicts between members of our species? Even within complex societies, fighting and killing your way to the top was the norm for the vast majority of human history.