Simple. Beer.
“Beer”
It may be that simple. That and war. Farming feeds more, supporting larger armies, and providing more time to make better weapons. Larger armies and better weapons win wars.
“It is only more confusing because the shift happened independently in about a dozen areas across the globe”
It’s very multiculti to say this, but farming began in the Levant at least 6000 years before anywhere else. It one thing to assert that there were different centers of origin for various domestic crops. It’s quite another to assert that the idea of farming hadn’t already spread to these centers before the farming started.