When did Vegetarian diets become popular?

https://foodandnutrition.org/from-the-magazine/the-history-of-vegetarian-diets-explore-the-progression-of-plant-based-eating/
Hubs and I were discussing this over dinner last night. Humans have the teeth of omnivores and early man was forced to hunt and forage (nomads) before agriculture got popular…… so, it stands to reason a plant-based diet is a relatively recent development as far as our culture goes. This article talks about the Greeks and Japanese discouraging meat consumption all the way back to 304BC!