Misinformation? Tssssss. Human brains grew because we ate HUGE animals which provided tons of marco nutrients and fat essential to BRAIN growth. You do not find these in plants in sufficient amounts.
Animal fat consumption and the growth of our brain are pretty much directly related.
'The prevailing view, supported by a confluence of fossil evidence from sites in Ethiopia, is that the emergence of flaked tool use and meat consumption led to the cerebral expansion that kickstarted human evolution more than 2 million years ago. Thompson and her colleagues disagree: Rather than using sharpened stones to hunt and scrape meat from animals, they suggest, earlier hominins may have first bashed bones to harvest fatty nutrients from marrow and brains.' (sounds like a very vegan thing to do)
'Humans are the only primate to regularly consume animals larger than themselves. This nutritional exploitation, something Thompson and her colleagues call the “human predatory pattern,” has long been synonymous with the flesh-eating, man-the-hunter view of human origins.
Because large animals such as antelope pack a serious micro-and-macro-nutrient punch, scientists have thought their meat contributed to humanity’s outsized brains.'
https://www.scientificamerican.com/article/fat-not-meat-may-have-led-to-bigger-hominin-brains/
Go Vegan and head back to the Stone Age, literally. Now please, STOP SPREADING YOUR DISINFORMATION.