It's proposed in a Niven-Pournelle novel that grain domesticated humans: we gave it the largest premium territories, we carefully propogated the finest varieties, and we elevated it to a holy sacrament and a symbol of sacrifice, divinity, and unity.

An often missed point about grains is that distilling or fermenting them into beverages made for easier transportation, storage, and resilience. Yeah, you could store grains in granaries nearby, but there is a lot of volume that makes it unwieldy for ox carts or train cars. If farmers can bottle their excess grain, then there is a diversified portfolio that can smooth over crop failures or market dips.

Of course, today the tail is wagging the dog, because liquor production is demanding far more than just the excess harvest or a portion to transport. But you can see historically why its benefits were being touted to the consumer.