72 and my knees are giving me some issues. I have a gravel bike and a hybrid that I ride depending on how my back and legs feel. I ride about 10 - 12 miles at a time with a 15-mile ride once in a while. My knees are my limiting issue and I do not recover like I once did. Hope I can ride for many more years and I will certainly consider an e-bike if the need arises.
Be safe all.