I worked in grocery stores with people that I would argue are smarter than many of the devs I have worked with. My old manager when I was younger and working in a grocery store was on a path to be a medical doctor, but changed paths after his friend killed himself from the the stress of medical school.
Intelligence is only one of the many variables needed to succeed in certain occupations.
It's absolutely perplexing to me that people seem to think that it's blindly OK to generalize purely anecdotal data as absolute objective truth.
Although you have zero supporting evidence for this fatuous assertion, you're perfectly fine with passing it off as empirical data. If you actually took the time to speak to your average software dev particularly in America, you would find that it's more likely that they've worked customer facing retail when they were younger. These are pretty much the only types of jobs that are available during high school. I myself have worked at Walmart, Blockbuster video, Chick-fil-A, and as a landscaper during the summers. None of it was particularly taxing - although it was extremely tedious at times and often boring.
And while we're on the subject of anecdotal data I would say on the order of at least 60 to 70% of software devs that I've worked with in the past were actually in relatively good shape physically and usually were very conscientious about their diet and maintaining regular exercise.
We really need to be filtering people back to Reddit.
Intelligence is only one of the many variables needed to succeed in certain occupations.