I too had the same diagnosis, spondy at L5-S1 in 2014. A top surgeon at UCSF.
You are correct as it "did the job" to straighten the spine, but nothing for pain. I recall talking to a PA affiliated with him on our way to a tennis tournament in 2016. They did their work, and I moved out of state. Since then, I have seen many ortho's and neurosurgeons, procedures, and fitted with a spinal cord stimulator almost two years ago. That too isn't helping.
All I can do is stay active, and work on PT exercises for now. I am seeing a neurologist at Mayo in Phoenix, and "jumping through the hoops" for insurance, to see what the next step is.