I would like to bring up a point often missed with blue collar housing work (plumber, electrician, dry wall, etc). It is EASY to start your own thing. Once you are licensed and bonded you can quickly buy your own truck, hire an apprentice, setup yelp, setup an online receptionist and be overbooked. Right now plumbers are hard to get and electricians are months out. The plumbers I work with cannot keep up with the work and make over $80 per hour (no where florida). If "Bobs orlando plumbing" runs out of work, they just park the truck. There is NO overhead.

If you contrast to an attorney or doctor -- those firms/practices are extremely challenging to start and operate on your own. The salaries of your employees are high at best, marketing is extremely expensive, and insurance can wipe out a firm/practice.