Admittedly TikTok is China-owned, and China already bans multiple U.S. based social media companies.

A number of countries already ban specific social media sites, including US based social media sites. In many cases, the core issue is that the country wants foreign social media sites to obey local laws and instructions on what to ban. And if the social media site refuses, it is just wholesale banned.

Leaving aside whether this is good or bad, I do foresee a world in which there is diversity in the number of social media sites, and their usage divided along country lines.

Also social media sites themselves have built many bubbles country wise.

Yes, the Pandora's box is opened. We no longer have the moral authority to blame other countries banning US apps or companies.

You think a little hypocrisy will get in the way of political posturing? It never does.

Hasn't China been doing that for years?

If they knew what was good for them maybe.

"Just did"? Facebook has been banned since 2009 in China.

they're already doing it and at scale

No, they already do and don't need our examples to follow. You don't read much, do you.