The real difference is not the logo
These apps do not really compete for entertainment. They compete for one scarce resource: your attention.
TikTok
TikTok was built around the algorithmic feed from day one. That makes it especially effective at turning micro-signals into longer sessions.
Reels
Reels combines short-form addiction with social comparison, identity and status display. For some users that makes it even more corrosive.
Shorts
Shorts imports short-form compulsion into a platform that used to support more intentional viewing, which can erode focused use of YouTube itself.
Bottom line
If you care about raw compulsive pull, TikTok usually comes first. If you care about comparison-driven distress, Reels may be worse. If you care about contaminating intentional media habits, Shorts is a serious problem.
For practical next steps, continue with how to break the scrolling loop and how to recover attention.