Electrician generally requires a number of years working under supervision in order to get your apprenticeship, journeyman and then master status. A not so insignificant part of that supervised work is just digging trenches or other hard physical labor and not actually running circuits or wiring things and you're not really allowed to do solo work until you're a master electrician so starting your own company takes a while at relatively low pay, long hours and hard labor. It's tough to transition to later in life.
In the US it's common for entry level or apprentice to be the ones making a trench on residential jobs. It's part of the hazing culture, my best guess, that the older workers pass down. I hired electricians and they did the trenchwork with shovels.
