Don't you have to do both?
I see pros stay low on low shots and try to maintain balance. But during a dynamic point, you need to move dynamically. I see Nadal scramble backwards and hit off the rear foot. I see Federer jump to lower the contact point. I see Djokovic lunge to get to a ball with funny spin.
The sit-and-lift motion is not wild. It is a controlled jump and you should maintain balance. During a dynamic point, you're going to have to move aggressively against a big hitter.