Yes, I know we all like crushing someone with a heavy topspin stroke, but slicing can be one of the best weapons in your arsenal both against fat people and young people.
Using slice means the ball bounces/skids low. Fat people can’t bend down low to get it so they drop their racket head and usually muff the shot. If they do get the ball back, they have to hit up on it which makes an easy shot for you.
Young people are used to seeing their friends hit them heavy, high bouncing topspin shots. They can regularly be seen actually jumping up to hit the ball with their full western grips. A full western grip is a lousy grip to use against a low bouncing slice. You will frustrate the heck out of young people when you slice them to death.
So, get out there and slice like crazy!