Zheng He’s fleet, and the ships in it, were on a scale that wasn’t matched until the 20th century. There are populations of Chinese ancestry on African islands from one of his ships that wrecked. His voyages put Marco Polo to shame, and some folks believe he even reached the New World.
The Ming government ordered his ships burned and his records destroyed in the belief that China had all the wisdom the world had to offer and all this running around was a waste of time. Which leads to an important point: The critical prerequisite for discovery is curiosity.
The world would be a very different place if China hadn’t managed to end up with some really ignorant egocentric rulers along the way.
The great First Emperor did major damage to China’s future when his paranoia drove him to destroy records of things rulers before himself had done.
...but the moral to the story is that government intervention always eventually results in decay.