This is a strictly American thing
If by "American" you mean North American, then yeah, you are correct, because pickups are also super popular in Canada and Mexico. But I don't think that's what you mean. I think you mean to specify the US which again, is incorrect. The fact that pickups are so popular in Canada and Mexico as well tells us that contrary to what I suspect you're trying to imply, there isn't some kind of special innate idiotic pickup truck gene that's unique to Americans and that instead, it's all about marketing.
After all, if marketing and advertising didn't work, it wouldn't be a multi-billion dollar industry. What the big American car companies have done with amazing effectiveness is to make owning a pickup truck an intimate part of a lot of people's self-image. That's what you are arguing against and that's why it's nearly impossible to change anyone's mind about it.
Also some of them are paid very well. Any of your unionized specialty trades can easily make $150k+ a year, especially if they're willing to travel or work a lot of OT. If you're single or married with no kids, you can pretty easily afford a big fancy truck like that.
If you're willing to travel that can be more than $50k a year in per diem pay, so in two years you can easily pay off a new trailer to live in and a nice truck to haul it with. I personally know people who have done exactly this. The catch is that you need to get into a good union and do your apprenticeship and generally have your shit together. It always surprises me that more people don't know this.