(Apologies to my son in law,the plumber)
My brother-in-law is a doctor in Southern California specializing in infectious diseases. Whenever he gets haughty, I remind him that plumbers have increased the life expectancy of humans more than doctors.
I also have some kin that happen to be Physicians.
At graduation, the speaker reminded them not to get too excited about becoming Physicians, he then stated that in 1900 the average American lived to 65, today 75. A gain of ten years.
Six from modern plumbing, two from food sanitation and two from modern medicine. ( I do not recall the exact numbers, but close)