The dreaded Erectile Dysfunction

In the fact it is credible and function can be preserved till the very grave; a problem is that with time sex is performed lesser and lesser and without the practice - a magic is gone.
Like with everything else, unless you maintain circulation in that part of a body - it dies.
It's not only with that, the older people in general refuse to maintain their physical activity, to practice, run, do yoga, swim and go to the gym - while ones who do, don't have any problems.
Also, your elderly spouse won't be really willing to perform more than XX times per month ( or year), which is rather sad but women do tend to lose interest due to a sudden hormonal drop so they don't think of it as such an extremely important thing to do.
In some circles it is found rather inappropriate to say that you have a normal healthy sexual life at the age of 60 or 70.
It is like a taboo.
Sorry to be cruel, and I exclude by far the people who have the health issues of any kind.
I am only saying this because from my experience my older male friends don't want to have sex so often, it is true, but usually even when they do want it, their spouses are nowhere close to be persuaded.