Builder has to have a certain amount of luck, too. Bond markets can be like Indonesian tsunamis to a builder, who's over-extended.
I know about the ups-and-downs of building. After growing up with a residential builder father, my younger brother found a niche that is less subject to business cycles, and is highly profitable.
That is insurance repair. Fires, floods, etc. He mastered it, built his firm up to 4 locations, dozens of employees and semi-retired in his early 50s.