It's debatable. Tiktok like other social media could be actually causing harm by a) being addictive, b) causing mental health issues, c) ruining your brain reward system, d) giving you adhd, possibly.

Once you start scrolling there, it is very difficult to stop, and I have tried it, but I don't think at least for me, it would add any actual value to my life even if I can't stop myself from using the app.

There's other entertainment, that I would think is more healthy, meaningful and can improve you as a person, so any time spent on Tiktok, I think is straying away from that other type of media.

So Tiktok definitely has impact, but I don't see how this impact is more positive as compared to say reading books or similar, which could potentially also provide infinite entertainment, but I also improve your brain