China censors what its people sees on its platforms so its people started using facebook. Then China started demanding that facebook censor itself in China (there was a major terror attack that sparked this) but Facebook refused so they banned it. Same thing happened with reddit and such.

Meanwhile, the US started censoring its major media platforms people either fled to niche libre sites like this or the shiny new addictive app from China. China doesnt care about what americans see. It'll happily let americans see Israelis document their war crimes. The US said, sell to american investors, and be censored or be banned. ByteDance chose being banned. Welcome to the great american firewall.