Printing money is faster and easier than digging up gold. If you think about it, they can print as much money as they want, but gold is limited supply. The amount of total gold the earth has is fixed. You can dig them all out sooner or later, but you cannot get more.
China was a major gold and silver exporter, but in recent years, it becomes a major importer. Central banks also went from gold sellers to gold buyers in recent years. They are expecting eventual debasement of dollar. They have been selling dollar. Anyone smart would be selling dollars. Billions of new dollars are printed every day. Why would anyone want to keep dollar? LOL. Better switch to gold (GLD, IAU) and silver (SLV, SIVR) if you want to keep your wealth.
Personally I prefer silver because of the industrial usage of silver is depleting silver very fast.