If that is the case, then so many people should be using Twitter and Google in China, where they are banned. Fact is 99% of people will not bother using a VPN to access TikTok -- anyway clones will appear pretty soon and they will grab the market.
I follow some pretty popular vlogs of village life in China with shit ton of subscribers. I can only assume VPN usage in China is a lot more common than most people think.