The “feck” in feckless began as a short form of effect used in the Scots dialect. So feckless essentially means "ineffective," but is also used to describe someone who is irresponsible, incompetent, inept, or without purpose in life.
It is surprising to realize how many feckless people inhabit the earth.
After interviewing 5 feckless applicants of various ages, I eventually hired a young person for the job