I don't see how that is relevant here. I'm guessing relieving financial stress is really effective in some too.

So what?

It doesn't help all patients, which means that we just can't cure everyone with exercise. Hence, we'd be worse off without them as some folks would suffer more.

It's relevant because there are a variety of therapies available. No single treatment will work for all patients. Medication is sometimes appropriate but it isn't always the best option.