If every one went vegan like vegans do, then there absolutely wouldn’t be a lack of impact, what a bizzare thing to suggest?
If everyone acts like you and goes “ah well, I can’t change anything”, that flawed “logic” can be used to commit any number of atrocities.
I do like that “scientific evidence” argument though. Like, “sorry judge there’s no scientific paper decrying killing people with a car so I did it”. You don’t need a scientist to tell you to do an objectively good thing - in this case stopping the unnecessary culling of sentient life for your tastebuds.