Although they control 60%, it's only because they refine 60%. They don't own it. The top producers are Mexico and Peru. If other countries could refine, China wouldn't corner the market.
I already did my research. China owns 60-70% of global silver supply. Silver is a high conductor and is in almost everything related to tech including the motherboards. Very important component of leading AI. Here's some findings. China is playing chess rn with limiting exports starting 1.1.26
https://blossom.primal.net/06fd176eaab388ecfa3602ec56f681af3242cb053934b97ecc3d3670493d8d5c.mp4
Discussion
Same for most things. China has worked to corner markets and dominate entire supply chains.
And kudos to them for that achievement, because they surpasse the next suppliers by a large proportion