Well, all of you will have a host of different experiences and opinions about how we age and how it affects our sex life. To say the least, it is very complex.
There are differences in how men and women age and how that affects their outlook, health, and behavior.
On average, men and women have different perspectives on their health and how to take care of themselves.
Testosterone in men and estrogen in women have a significant effect on appearance, sexual aspects, and mental health.
In our youth, we get away with the facts of being young: looks, sex drive, and even personality. However, as the years roll on, differences may crop up that have significant effects on a relationship. My wife and I were very fortunate to remain compatible (at least until her cognitive decline). Suppose we honestly discover that the one we are with and ourselves have matured differently, and we can not stay together just because of emotion and tradition. In that case, we must seriously consider making a change. However, your situation requires it. My wife and I know how hard this is. She is my third wife, and I am her second husband, so call it divine intervention, fate, or blind luck. We formed a relationship that accommodated our changes, and we now have been married for 39 and one-half years by the end of the month.
So what can I conclude with here? If you are enjoying a good quality relationship at whatever age you are now, be grateful and try to work to make it absorb the changes that life will toss at you. If you need to find a new significant other that is compatible now, and hopefully, as time goes by, you will be up for a serious challenge and a daunting quest. All the best to you. Remember, it can be accomplished, but knowledge and experience are required for the best result.