Thinking like a business vs. thinking like a state.
If you see a given technology as fundamental[tm], you want to ensure that you will retain access to it AND its ongoing development. China may well foresee a possible future where US imposes export controls and global sanctions to block PRC from having access to the necessary equipment to either train or use the most advanced models - let alone its alternate parallel universe where US might go as far as prevent anyone else than US themselves having the most advanced forms of the technology at all.[ß]
To ward off such a scenario, China doesn't need to become the sole leading supplier. They only need to guarantee that nobody else can even try to block them off, and that the technology itself can never be yanked.
ß: What could possibly give them such ideas?