Description of lumbar MRI: "L3/4, L/5, L5/S 1 disc herniation, corresponding horizontal dural sac compression." That is to say, the nerve roots of the lumbar spine are not obviously compressed, and the degree of disc herniation is light, only reaching the outer membrane of the spinal canal.
Your father is 74 years old, and the MRI results of the lumbar spine are so good that it can be said that the lumbar structure is not bad. If you don't feel well, you can go to the clinic for physical therapy or rest. There's no need for surgery.