waster
A person who carelessly wastes time, money, or other things.
A waster is someone who squanders time, money, resources, or opportunities without care or purpose. If your friend spends all afternoon scrolling through videos instead of finishing the science project due tomorrow, they're wasting time. Someone who throws away perfectly good food is a waster of resources.
The word carries disappointment and frustration. When a talented athlete skips practice and never develops their skills, coaches might call them a waster of potential. When someone fritters away an inheritance on foolish purchases instead of using it wisely, they're being a waster of money.
Waster describes a pattern of carelessness or laziness, not occasional poor choices. Everyone wastes time sometimes, but a waster does it habitually, without concern for the consequences or the people affected.