Since I am no doctor, and I don’t know you, and even if I did I still couldn’t really answer this with any authority, let me answer as best I can from the body of knowledge that I have.
First, it depends. That’s as different and unique as a fingerprint.
Second. Your knees are likely to do well (see https://medium.com/crows-feet/but-running-is-bad-for-your-knees-1208f23e5103) Even then, it depends. On you, your knees, your gait, your weight. Listen to your body. If it whispers, keep going. When it shouts, stop.
Third: More isn’t necessarily better. Again, it depends. I love to go longer but that’s me and my slow twitch fibers. Some folks to better with HIIT. What works for you won’t work for me. I have an elliptical and it’s lovely on my sore joints. I also run in the pool. Run, not swim. That’s very kind on aging joints and it’s fun.
And fourth: what feels good, gives you both pleasure and results without either causing pain or injury? That’s completely up to you. Those who like to dictate to others what they should or shouldn’t do don’t live in anyone’s body but their own. That makes me suspicious. Experiment, see how you feel, add or subtract different exercises, speed and distance. More isn’t always better. Sometimes faster is, or harder. Changing things up sometimes is terrific. It depends (see a pattern here?)
Again, this is your body Ted. Nobody knows it better than you do. All else is speculation and anecdotal. Only you can find out what’s best for you.