This. What held up wheeled luggage was the difficulty of having small, reliable wheels that could bear a lot of weight. You could have big wheels, but that woul

This. What held up wheeled luggage was the difficulty of having small, reliable wheels that could bear a lot of weight. You could have big wheels, but that would be impractical here, though not for chariots, wheelbarrows, pushcarts, or rickshaws ... which did exist in antiquity.