And you know what? You can sit in a chair and read books for the rest of your life and you can still get arthritis, you can still have heart attacks and strokes and I can guarantee that at some point in time you will die.
So let's see if there can be a case mounted for jujutsu or judo. Mostly these throws are trained on good mats so although there is a reasonable amount of falls they are break falls and rolls so they become part of the exercise giving an aerobic workout as well as the physical, and the force of the fall is largely taken by the mat.
Joint locks? Sure they put pressure on the joints but they also act to stretch everything as well. The more you practise the better you are at having them applied and in the case of shoulders you may well find you develop greater flexibility.
As to the
very high kicks, spinning kicks, rounded kicks, jumping kicks and flying kicks and such, why do them at all?
From a personal perspective I damaged my back over 50 years ago as a gymnast. It plays up from time to time but is no worse now than it was decades ago. I have a weak elbow. It wasn't caused by any of my training but was damaged by a Hapkido guy, 4th dan, who couldn't make his technique work. My fault for telling him I would go with him and he applied full force on a compliant partner. Not the fault of martial arts, just an ego problem for the practitioner.
My shoulders? They are as stiff as stiff but I reckon they would be worse without the stretching they get when we are applying arm locks. Knees? Sure they creak and groan but I reckon they were damaged more by lifting heavy weights than caused by any martial art. Mind you, I don't like kicking air like you see in a lot of training. That certainly is bad for the knees.
Pinched nerves? You can pinch a nerve rolling over in bed. I have had pinched nerves in the past but to the best of my recollection, never in MA training. Arthritis? What's that? I've got lots of mates with arthritis who have never seen the inside of a dojo and I seem to have missed out. Sure I'm a little stiff in the joints when I've been immobile for a while but give me 10 seconds and I'll come good.
So there. I might be living proof that spending decades in martial art training, which had left me ten times fitter, stronger and more flexible that most of my friends who have not done MA training, is not harmful to your body. Then again, I'm only 66 so I don't know what I'll be like when I'm old!