The comparison isn't even close. TikTok's relationship with the Chinese government is well-documented, not "supposed". They are legally required to share data under China's National Intelligence Law. The Chinese government has also a track record of pushing disinformation and find any way to destabilize Western democracies.
Douyin (The Chinese Tiktok version) limits users under 14 to 40 minutes per day and primarily serves educational content, while TikTok's algorithm outside China optimizes for maximum engagement regardless of content quality or user wellbeing.
US tech companies pursuing profit at the expense of user wellbeing is concerning and deserves its own topic. However, there is a fundamental difference between a profit driven company operating under US legal constraints and oversight, versus a platform forced to serve the strategic interests of a foreign government that keeps acting in bad faith.