I think there are two main reasons why China's cultural relics are scattered all over the world.

The first reason is that in ancient times, although China's science and technology were not so developed, China would also make friends with people from all over the country and foreign countries. In the Tang Dynasty, there was a saying that Yang Guifei went to Japan, which was not groundless. It can be seen that China had contact with other countries at that time.

So at that time, it was not impossible for China to exchange its cultural relics with foreign countries to show reciprocity.

Another reason is that Eight-Nation Alliance invaded Beijing at that time. At the end of the Qing Dynasty, due to the corruption and incompetence of the Qing Dynasty and the closed door at that time, China was far behind other countries.

So when all countries in the world have developed science and technology, and China is still in the most backward stage, they can only be bullied if they open the country. At that time, Eight-Nation Alliance invaded Beijing together and burned the Yuanmingyuan, ransacking all the treasures in it. They all moved away if they could, but they couldn't, and they all smashed it, and finally burned it all.

After the Yuanmingyuan burned down, Eight-Nation Alliance removed all the cultural relics from China, and they also conducted an auction without scruple. Up to now, we haven't found all the zodiac signs. So it is because of their brutal behavior that China's cultural logistics have fallen to all parts of the world, and their whereabouts are still unknown.