China is an EU sized country with even larger economy than EU, so by itself it is already a network with a lot of regional advanced economies that are individually larger than most smaller countries, it is very hard for any outside MIC to compete against them.It makes sense for the US to import from their allies, in fact, that is one of the reasons for maintaining those relationships. The only reason China has to be 100% self-sufficient is because it lacks a global network of allied countries with advanced economies capable of specializing in certain technological areas.
Even though China can import from say Russia, it is not that surprising that the best stuff China can get is also locally sourced, basically if EU had an unified army they'd take the best from France, Germany (and UK before UK left lol), and they would largely be 100% self sufficient.