Bytedance doesn't make Chinese TikTok "educational" from the goodness of their heart. Chinese companies were happy to let teenagers play video games from dusk till dawn until the CCP got involved, not because Tencent wants American teens hooked on league and Chinese teens studying.
TikTok is always painted as some masterclass psychological Chinese weapon instead of it just being a failure of our own American government to do anything but stalemate and worry about bathrooms. There is no reason to believe that if TikTok is banned that Instagram wont supplant it in serving up the same garbage to users (except no one would complain because the gripe about TikTok is xenophobia for most people, not any principled stance on entertainment).