They’re Designed To Be Addictive

Feedback Loops: Games often provide immediate rewards for accomplishments, which can stimulate the brain's reward centers and create a desire to continue playing. 

Daily Rewards: Some games have systems that reward users for logging in daily, encouraging habitual use.

Social Features: Many games have social components like leaderboards, multiplayer modes, or the ability to share achievements, which can create a sense of competition and community.