In Tiktok’s case, it has been shady for years.

There were already reports Tiktok censoring dissent in 2019 when it just starter gaining popularity internatinally:

• Revealed: how TikTok censors videos that do not please Beijing
• TikTok’s Beijing roots fuel censorship suspicion as it builds a huge U.S. audience

And even earlier, Tiktok’s parent company operate and had its headquarter in China, so it’s forced to comply with the Great Firewall of China, and participate though their own moderation/algorithm.

Using a media that’s operate (in part) in totalitarian state with heavy handed censorship doesn’t make sense. Even if they have some infrastructure elsewhere, it’s still owned by and answering to ByteDance management.