I remember the talks at the circuit assemblies where they interviewed young brothers who started their own window washing and carpet cleaning businesses and what a blessing...they could make good money doing jobs that "worldly" people didn't want, and they had time to serve Jehovah.
Years later they found that they have a ton of competition as many "worldly" people found they could also make good money doing the same thing.
Many brothers also developed health problems which made it difficult to do their job. The could hire employees, usually JW's, but they weren't always dependable.