I have a LaserMax on my Glock 17 as a secondary/tertiary targeting aid.
At 15 yards or so you hit within 2-3 inches of where the laser is pointing. You won't always get a good sight picture. The laser can assist with hitting the target in those cases.
I have a hard time seeing without my eyeglasses, but I can still pick up the laser and hit the target without them.
If you have perfect eyesight and always shoot from an optimal shooting position then I suppose it won't add much value. That doesn't apply to me, so I also have a laser.