Their UI has been refined a lot over the years, with each update making it more satisfying to click on notification bubbles.
Additionally, because the community is so large and the algorithm so good, you can literally find almost ANY niche you like there. People who haven't used the app for long complain about the content being mostly dances and pranks, but the truth is that if you use the app consistently, it'll figure out a dozen super specific-to-you niche topics within a day or two. For instance, I'm part of the VFX, filmmaking, art, and music production sides of TikTok because those are my hobbies, but I also routinely get candy making videos, absurdist comedy, and animations, things I didn't know I loved until I downloaded TikTok.
Overall--if you have a history of social media addiction, use it with caution. If you're not afraid of getting sucked in for hours at a time, it truly is a wonderful platform full of stellarly creative people.