There are over 80 million US downloads of TikTok as of October 2018, with an active user count of 40 million [1]. This means China's authoritarian regime is influencing the political discussion of 40m+ US citizens.
You say this ban is good, I disagree. In the US, a lack of informed political discussion is one major factor keeping young voters away from the polls. It also prevents global free speech from reaching 400 million Chinese users.