Rome was unusually superior to its rivals. Chinese, Indian and Persianate empires occurred again and again. Rome happened once and was never reassembled. Great big plains where you can grow lots of food are a much better foundation for an enduring empire than a sea where almost all of the connecting land masses has mountains nearby. I’m not aware of anything similar to the Punic Wars happening elsewhere until the Hundred Years’ War. That’s staggering levels of state and popular commitment to war, for a very long time.

Rome was in fact special.