[codeflow2202]

You are supposing that recipes were passed down through books which is totally false. They were passed down in families and communities and were based to what was available at the time. Meat is more prevalent in recipes coming from regions where it was more available. Some other places have instead a fish based diet. In any way animal based food has always been preferred by every culture that didn't avoid it for religious reasons. Most cultures who have a plant based diet come from a recent past of extreme poverty and food deprivation.

EDIT: Of course as soon as meat got available, recipes that were before only affordable by a small circle, got picked up by a larger share of the population.