Netflix and Amazons' advantages is they are always reaching out to the global market and competing in as many countries as they can, rather than just stay in the US. Thus they have billions of potential users even though the US population is only 330 million. Tik Tok is a successful Chinese company that has branched out, but the problem is it relies on the Google Play Store and Apple App Store outside of China so it can be banned at any time by the US in markets outside the US.
China needs to develop its own app store ecosystem outside China and also a global community of developers for those apps. Then apps like WeChat can branch out globally. This is what Huawei was trying to do when it got banned.
However, that doesn't stop Chinese streaming services or online retailers from branching outside of China, since they don't rely on mobile apps.