Having any degree and some social skills can get you a white collar job. While not glamorous it beats shoveling holes (unless you're smart/practical/brave enough to make good money with some sort of physical labour).

That's useful to you since you can make a somewhat easy living. Useful to society? I mean sort of, in most jobs you achieve _something_. The fact that we're inefficient and often build the wrong thing that's useless is more of a failure of the human race in general..