Where I grew up in Texas, the time and place, almost everyone did their own handy work. Their were illegal immigrants around, but they weren't doing any work that white people/ black people, etc didn't also do...Mostly teenagers/ 20 and 30 year olds that grew up around my hometown did the real grunt work on ranches and in the oil field...I made money for college doing all kinds of manual labor jobs from working in the oilfield, welding, framing houses/ barns, painting, hauling hay, working cattle, etc...
You could be right, the whole world might collapse without the cheap labor, but it didn't back then and there was way less people in the country illegally in the 70's and 80s..
Anyway, I didn't imply we don't need those kinds of manual labor workers here in the US, what I said was immigration needs to be controlled and maintained in the country by us, our government..Way better than it is now.
I couldn't or maybe don't know to get away with paying an undocumented immigrant to do major work with insurance money on any of the houses i've owned. They always asked for licensed contractor everywhere I've owned a house.