Anecdotal. While I was in Netherlands I was quite pleasantly surprised to see so many old people, judging by their looks 70+, cycling to their daily chores. They seemed quite fit and mobile just fine to me. After a while I stopped being surprised because I realised it's a common occurrence there. So make of this what you will.

No, quite the opposite. Cycling is a very low impact activity, especially compared to running. Many runners get on a bike to develop or maintain aerobic fitness when they are healing from overuse injuries like stress fractures.