If the guys heart is not in it , then its time to move on...
no matter what line of work you are in, if you are unhappy, its time for a change... sometimes , even regardless of earnings... as your health and happiness are more important.
i dont agree that because you are out , working "on the tools"... you will never be wealthy.... you have to put the groundwork in, the graft... the long hours.. sometimes for a while you even absent mindedly put your family on hold.
That can apply to any business starting up... the hard graft and leg work needs to be done... before any rewards are achieved......
so working in the field, learning , learning building , building .... is important in any start up business, then you can or may reap the rewards.