Sitting leads to 40 to 90 percent more stress on the back (disc pressure) than standing posture. – Cornell University Ergonomics Web
Sitting for long periods of time can cause pain from joint misalignment and muscle weakness.
The constant relaxation and weakening of the hip flexors which control the pelvis and the lumbar spine puts your back under constant strain.
This can then cause the hamstring muscles to compensate and that weakens the gluteal muscles that are meant to stabilize the back and pelvis.
We tend to do more hip mobilisations with a lot of people we treat who have a more sedentary job.
The influx of "work from home" cases post covid reinforces these points.