I drive an older car. I've driven older cars for quite a while. Often it is because I don't have a choice, but I also have learned that these older cars are often just as functional as the younger ones. Yes... I said younger, because I'm using this as an analogy to people, as well.
There has been some judgment for a long time about older men with younger women, though it is becoming more common, but it is also common among women. In my years of being on dating apps, I've seen MANY women's profiles that sometimes EXPLICITLY says they want men at least 5 years younger than they are. Both older women and older men are visualizing their mates as being as fully functional as they were when they met their first husband or wife, even though they are no where near that mark, themselves.
I've done posts about entropy, before. It says that things fall apart as they get older. This will happen to the bodies of people, too. But, when it begins to happen, those people are often replaced, because they no longer can do all that they can do. Forget the wedding vows of "for better or worse, richer or poorer, sickness or in health"... if you are not better, richer, AND in health, you are disposable.
I also want to emphasize why I said "AND" in caps. Our culture is taught to look for fault... not the good in things. You can have 95 percent good but if there is something that is wrong, that becomes your defining characteristic. History together, memories, and more are not even considered, because when someone WANTS to find fault and judge, they will just say the other person "changed" and discount all the good.
It is impossible for people to spend time together without people finding SOMETHING that they don't like about the other, which I think is a reason our divorce rate is as high as it is. What is much more rare are people that learn to VALUE the good in each other and find reasons to stay committed. Many dating profiles I see LEAD off by saying, "I don't want anything serious." Then, I would bet you probably won't find it.