Rather than blindly pursuing self suffeciency, it is better if China work with European or other countries' companies to replace US parts in their products that are exported to China. It is better if Chinese companies can replace the US parts, but if they can't, China can invest in foreign non US companies or start up that can. Take Huawei for example. If Huawei want to break the google and other US companies embargo, Huawei should invest in and promote foreign non US apps, help EU develop their own tech champs, make google and other US tech irrelevant in global market. It should not be too hard since EU and others have begun to feel wary of US tech giant dominance.

That will prevent the other non US companies from joining the US, and it will hurt the US more if the replacement can be found, not to mention it will save a lot of resources for China. Chasing self sufficiency in every thing will only alienate your trade partners, not to mention it will take much longer time and huge resources, and with uncertain results.