One of the reasons to change the recoil spring is to help protect the frame.
Most manufacturers recommend changing the recoil spring every 5000 rounds. If the recoil spring gets weaker, the slide comes backward at a greater velocity and bangs the frame harder. With a stronger recoil spring, the slide's velocity is better controled and the frame takes a softer punch.
Just be careful and use a replacement spring that is too heavy. On lighter loads the slide might not go all the way back causing ejection or feeding jams.