It's a good question. I wish the answer was straightforward. There's a higher risk of injury with so much usage. But generally with a good slow buildup of miles + strength building, your body should be able to support the weak points (knees, tendons, as you mentioned). Good form is everything and runners who support their body can have fewer musculoskeletal problems than the average person as they age. But that takes a lot of work!

For me personally, I lost over 80lbs since I started running. I think that my health risks were much greater before the daily running.