I think people often conflate "being a <trade>" with "owning a <trade> business." A W-2 electrician earns a median salary of $62k in the USA. A guy who runs a business as an electrician might bill out $250k a year for his work, but he'll have to pay expenses like insurance, vehicles, gas, tools/tec, FICA, taxes, rent, on call services, and probably salaries for his assistants (which may include an unpaid secret assistant like a spouse who coordinates appointments). So their take home isn't nearly that much.