Some people can go for many years without treating rotator cuff injuries, and then it seems like they start having more symptoms. This is what happened to my mom.
She had an old rotator cuff injury diagnosis, but did not have much problem for many years. I don't know if it was a combination of the old injury and arthritis from aging, but she eventually had surgery because the pain became too great. It seemed to be the shooting pains that became more frequent.
Surgery turned out to be a good option for her, as she has not had to put up with that type of pain since she recovered from the surgery.