As a recent grad, so many of my friends are heavily invested in TikTok and have been since quarantine began, some of them for a bit before. The amount of time they spend there is absurd. Consuming 30 second content for three hours can't be good for concentration, right? It helps add to the 'always online' mindset that has grown more popular with social media and smart phones.
Instead of going for a walk, some of my friends would opt to lie in bed and watch TikToks, creating empty, basically non-existent connections with people across the world. Connections with people across the world are awesome, and one of the best things about the internet, but TikTok connections are basically UDP.
Most TikTok content I've been shown is shallow, the same way so much social media content is shallow. My having to get to the point immediately, we leave out key details and we want to catch your attention before you scroll away. Of course there is the other end of the spectrum with YouTube where a 2 minute tutorial takes 15 minutes.
I try not to use much social media, and honestly, I probably should limit my time on HN more as well. Doom scrolling is a real thing, and TikTok is not immune to that. I've seen plenty of dread inducing content that comes from TikTok as well.
TikTok keeps you logged on, as it's supposed it. I just don't think that's a good thing. If you can control and limit your usage to something that's healthy for you, then I don't think there's a problem. For me though, that healthy limit is 0, because I know myself and I have little self control with social media in the past.