So as a man progresses through MRP; improves himself through lifting, diet, reading the sidebar, developing hobbies, bettering his career and finances, etc. why stay?

Let’s say the man is 45 and firing on all cylinders; he can start getting HBs in their late 20s; why stay with the 45 yr old wife (who might be hot for her age; but isn’t 26 and isn’t getting younger)?

I am looking for insight from older guys as to why they stayed and didn’t “trade up”