Actually if you want to get into the nitty gritty, without meat we would be another animal on the savanna.
https://www.sciencedaily.com/releases/2012/04/120420105539.htm
https://www.livescience.com/24875-meat-human-brain.html
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5417583/
https://news.harvard.edu/gazette/story/2008/04/eating-meat-led-to-smaller-stomachs-bigger-brains/
Read up.
Human’s digestive tract is fore-shortened, relative to great apes of similar body mass. Cooking plant matter makes more nutrients available with less energy expended for the digestive process. Consuming meat with pre-concentrated nutrients provides a further leap in efficiency.
That lower energy investment for processing the food intake enables fueling a large brain, which consumes close to one-quarter of calories ingested. Meat in general, not just fish, is the critical brain fuel.