WeChat, for example, is the end all be all megaplatform in China but never took off with any Western consumers simply because they’re uninterested.
It isn't insular, it's just it was the only local solution - same for Line having a lock on Japan and Thailand but not much of asia, and kakaotalk for Korea.
I don't think it overtook qq until like 8 yrs ago? At which point AIM was already discontinued, and 10 years past any kind of popularity.
The bottom 90% is owning an ever smaller share of the economy, while the real economy doesn't seem to grow that much.
It seems like you are comparing small companies vs large companies, rather than US vs Chinese.