I think it also depends on the person (their vision/health/etc.) as well as the surgeon's experience plus the equipment. The hours/days following the procedure are also pretty critical. You have to be very careful to not rub your eyes or anything like that and get plenty of rest while using the eye drops as prescribed.
If you don't like those risks then don't undergo it but for other people will find the risks acceptable and want to have it done. Being approved doesn't mean it is forced on anyone.
Is the point of a regulatory agency to decide for hundreds of millions of people what their acceptable level of risk? What if thousands of people die from not having access to medications that a regulatory agency deems too risky?
It's a very successful procedure, for the vast majority of people who undergo it. I fail to see why "it should never have been approved".