The US isn’t “blocking” TikTok, they are forcing the parent company to sell it
If they refuse to sell, then sure the US will follow through with a block… but that’s not the intention. I guess the question is how much does Bytedance care about their US market? The US is TikTok’s largest market, but it’s still only about 5% of TikTok users. There are almost as many Indonesian users, and Brazil isn’t far behind. Plus Mexico, Russia, Vietnam, Phillipines…
And some of those countries might not want a US company to control TikTok.
Zuckerberg has said he doesn’t think it’s possible for any social network to operate (with significant marketshare) in every country, which is why he’s interested in the Fediverse. If there has to be a wide ecosystem of social networks, then users should be able to access content posted to other networks.