It didn't fail, it worked perfectly for five years. Surgery adjusts the current state of the eyes, but your eyes may continue changing the same way your body does during your lifetime. That is why it's recommended that your vision has been stable - that is, you have had the same set of glasses without your vision getting worse - for at least two years. Normally, vision degradation over time follows an S-curve and flattens out after a couple of years. Only then does it make sense to consider laser eye surgery.
Imagine a body builder getting a tattoo on his chest. Then he stops training, muscles turns into fat and the tattoo starts looking like nothing at all. Did the tattoo "fail"? Your friend seems to have picked an appropriate time, but his body changed. One just needs to be aware of that, you can't put the blame on the surgery.