The biggest benefactor here is Meta. There's no way TikTok will remain a dominant social platform in the US amidst all the political meddling and so many high profile investors with competing interests.

This is likely also why Meta announced that they are overhauling Instagram to make Reels and recommendations the default experience - https://uk.finance.yahoo.com/news/instagram-overhaul-app-num.... Just as with Threads, they saw an opening and are doubling down hard.