Half Damage on Successful Saves

https://www.youtube.com/watch?v=hRcsmqeL7qA

Think about it this way -- if you were a fighter and every miss turned into successful hit with half damage, how good would the fighter be?

Wizard - Evocation - Level 6 - Potent Cantrip

Potent Cantrip.
Starting at 6th level, your damaging cantrips affect even creatures that avoid the brunt of the effect. When a creature succeeds on a saving throw against your cantrip, the creature takes half the cantrip’s damage (if any) but suffers no additional effect from the cantrip.

https://rpg.stackexchange.com/questions/144100/what-is-the-purpose-of-the-evocation-wizards-potent-cantrip-feature