The Comment Section Is a Second Content Surface
This is the structural difference between TikTok and everywhere else. On most platforms, opening the comments means leaving the content. On TikTok the video keeps playing behind them, looping, while the viewer reads.
The consequence is that a good comment section directly increases the time people spend on your video — and time spent is the metric the recommendation system cares about most. A video with a comment section worth reading holds people through three or four loops. The same video with an empty comment section gets one.
This also means comments are read far more carefully on TikTok than on Instagram or YouTube. People are not skimming past them on the way somewhere else; the comments are part of what they came for. Which is exactly why filling that space with rotated pool text is counterproductive.