Exercise is not a panacea, and those who say it will fix everything and cure depression and make you perfect are quacks. But, it pains my contrarian ass to say, some light cardio every now and again is much closer to what our bodies are happy with than desk life, such has been my experience.
Of course, that's going to be different for everyone. It'll make some people worse. For me, though (and apparently for you, too), it is the right way to treat those issues.
For those with knees not tolerant of running, I've taken to also rucking around with a heavy backpack. It's fantastic for building torso strength, and "your body weight plus 30 pounds" is still far less impact than "your body weight, but running". Walk up some hills steep enough to make you pant and wonder if you can make it to the top and your body may thank you for it, the way mine thanks me.
BTW, doctors have a saying: "motion is lotion". Also, "when you stop moving, you die". We are not evolved to take root on a sofa. Our bodies are meant to move and jostle and bounce and twist. Absent specific reasons not to, it can make a huge difference in physical comfort.