But, a professional plumber or mechanic is probably many times more efficient than I am. I recently fixed the air conditioner in my car by replacing a bad relay

But, a professional plumber or mechanic is probably many times more efficient than I am. I recently fixed the air conditioner in my car by replacing a bad relay. It took me about 5 hours to figure out what was wrong, figure out how to fix it, find the right replacement part and then replace it. A professional mechanic probably could have done it in 15 minutes which they probably would have rounded up to an hour which would still cost me much less than my after tax earnings for the 5 hours it took me. If it had been something more complicated that actually took specialized tools and more specialized skills, I probably would have come out even worse trying to fix it for myself. Even with something relatively unskilled like cleaning someone who does it every day is still probably at least twice as fast as I am which makes up for the entire cost of taxes even if my hourly rate is the same as theirs.