I know people who work(ed) construction who are actually very smart and they constantly belittle their own intelligence because they don't have a college degree or have a job that works with computers. Vice versa I know people who attend graduate school at tech institutes who are actually stupid in many ways but are so full of themselves because they've managed to memorize enough to pass engineering classes.

>Now look at long-term health and economic prospects of the two careers, beyod short term satisfaction with survivorship bias.

Economics seems to be the real reason the original poster saw people switch away from manual labor after trying it for a while. Construction workers may be happier and more fulfilled day to day, but software engineers are paid more and it's hard to say no to a larger, more consistent paycheck.