Earlier quoted context omitted.
You can build an app and test it yourself. It also isn't terribly difficult to extract the java side of the platform code.
How can you trust that there isn't a backdoor that's not available to you?
And Google and Apple are doing this because... why? Is Bytedance paying them a shitload of money? Are their CEOs secret CCP plants?
If you are concerned about this, how would even refusing to install TikTok protect you? After all, Google and Apple could simply collect the data directly in the OS and send it to Bytedance themselves.