The other things about standing around is modern machines get so much more done that most of the time it doesn't pay to work. A single scoup of an excavator is more than one person with a shovel can do in the day, so what is the point of even trying. Sometimes someone needs to dig by hand. Now it may seem like get rid of people, but the problem is every 20 minutes you need all those people to do something that must be done by hand, then they all work for 5 minutes and stand around again while the machine works.