Scientific study reveals TikTok videos deactivate key cognitive brain regions
(www.rathbiotaclan.com)
I honestly think speed has a lot to do with it. With the rapid switch and ability to just ping the next thing, it removes all reflection time.
Even flipping through channels required enough to evaluate what you were jumping into the middle of.
Algorithms make it so the videos are incentivize to onboard you as fast as possible and they start when you flip.