This is something I think all short form video platforms struggle with. I think I know why. Its because the difference in the UI. Basically, a user doesn't choose what to see next. On YouTube, you get dozens of next videos recommended on each view. On short form video, you get one. This causes clickbait to work a lot better for short form video. The problem with platforms like TikTok is more about UI than algorithm or the length of the videos.