How did you determine that? You have any idea how easy it is for a man 6 foot or taller to get over 275 if they work out or just work hard?
Honestly, it isn’t that hard, especially if you are over 6 foot. I am 6 foot myself and in my younger days of muscle work, over brain work I do now, I hovered between 270 and 285. In high school I was 190 before I even graduated and was a fit wrestler, as a boy / teen grows to real manhood that weight keeps increasing easily.
That was just from the calories needed and work required.
It's not a matter of how fit the person is. Have you ever worked at sea? The North Sea? Working a fishing vessel in the Gulf of Alaska is the most dangerous job in America. A guy 275 pounds in trouble on a deck covered with ice is too heavy for OTHERS to rescue reasonably without taking excessive risks.
It is a considered limit.