I'll admit we had some of that same crap around here at one time: A pipefitter on a large job had to wait for an operator to come start his welder. Only operators could change the oil on a back hoe. Those days are mostly gone. When we laid underground pipe in ditches we bedded our own sand in. When the laborers complained I'd tell them bedding pipe is plumber's work and they could have the rest of the ditch for backfilling. Besides them claiming it is was cheaper than a plumber doing it. Common sense ruled. One of the best times I had was when a laborer steward tried to stop me from shoveling white rock into an acid dilution pit for pipe that came out of a chemistry lab. He claimed working with rock was his people's job. I told him in this case it might look like white rock but it was being used inside the fiberglass basin as 99% pure calcium carbonate for acid neutralization. He agreed and had a good laugh. I told him his people could put the rest of it in around the outside of the basin as fill since it magically turned back into lime stone at that point!I'm not contesting that they work their a**es off, just that they don't want a laser screed around because it does the work of 5 or 6 guys with ease. Trowel machines are a necessity on large jobs to keep up with the curing, so they use them. Pumper trucks are also a necessity on tall wall pours, mezzanines, etc. Georgia buggies still need a guy to run them, so those are used.
What gets me is that when the concrete guys get to the end of a pour and have to put a 2x8 in to close up the part where the trucks were bringing concrete in......they aren't allowed to do it. They have to wait for a carpenter to come in and put that one board in. If it isn't your trade....even if you know how to do it and can do it in a few minutes.....you can't perform the work of another trade (no matter how small it is). I've seen it done, but they usually get yelled at.