I think TikTok's keys are ease of use - you can just swipe mindlessly, no choices, next, next, next, next. Good algorithm to predict a mix of stuff you'll probably like and new stuff so you can still explore the space. The combination of the two makes it addictive. You keep hitting that Skinner box and you get rewarded.

I personally used TikTok for a bit (only as a consumer) but had to cut it from my phone. It was too addictive. I found myself using the app for longer than I wanted.

While TikTok is entertaining I don't really miss it now that I've removed it. I feel lots of videos there lack substance.