This is hardly news if you're under the age of 30.
Tiktok is simply Vine but operated by the chinese government as a tool to collect Intel and shape public opinion.
If you are trying to get (young)people to use your app in this day in age you want it to be obvious that all of the hottest most interesting and influential people on social media are using your app. You accomplish this by curating the content of the app and its advertising.
I will try and find the article that talks about how a bunch of content creators were approached to join Tik Tok, specifically because they are physically attractive and have large pre-existing social media followings.
Go try and make a Tik Tok video about Hong Kong and see where it goes.