Let’s revisit geography for a minute. The Romans were agrarians because they had high quality soil and they lived inland away from the sea. It never occurred to them to use the sea for their own purposes until they were forced to deal with Carthage at the beginning of the First Punic War. Still, there was nothing unique in their geography that could ignite a new culture on its own.
Rome became fluorescent when it first thought of getting rid of the monarch. The Senate and Assembly were already in operation so all that remained was the creation of an administrative magistrate’s role. The healthy agrarian economy would fund the young Republic and take it places its founders could never have imagined, but it was the people and their will that served as the engine.