In my experience, men in their 50s and 60s have definitely not lost their mojo😉. I have often hooked up with guys in that age bracket at events. They never failed to please, and seem to give more time and effort to your needs. So I would have to say their desire and abilities do not diminish over time.
And there is my old gym teacher who is in his early 60’s who I love to check in on😏 when I visit back home.