Why are so many people content with just earning a salary and working 9-6 their entire adult life?

I worked the same job for 38 years.  Got to do something different all the time.   Had lots of vacation, sick leave , holidays and home every night.  Not a huge salary but enough to have a nice home, car and truck, no debt and a great retirement.  Been retired 11 years and get to do anything I want or go anywhere.
I've had the same wife for 50 years.  Our health is very good.
Now how could I possibly have improved on that?