The posture of the upper body does not only depend on the straightness of the spine. The spine relies on the sacrum/hip. The hip relies on the feet.
Thus back massage and snaps won’t influence it.
At the age of seven we sit down on a chair and spend many hours there daily.
How do we expect to sit with a straight spine, back later at our workplace on this sacrum which has already been misplaced in childhood?
Workout can enhance the muscle to a point where you won’t feel this scoliosis, but inside, your spine still has the same posture. And you strive to keep your posture by your desk. This is why you lean on the table, or keep walking around, and this is why it hurts.