Social programs often compensate for massive distortion in the economy. For example, SNAP benefits both the poor and the businesses where SNAP funds is spent on, but that's because a lot of unearned income goes to landowners, while preventing people from employing laborers and starting businesses. SNAP merely ameliorate a situation that shouldn't had arise in the first place.
So, yes, reasons other than efficiency explain why people aren't working, as well why there are still poor people.
Millions of working Americans don’t have cars. Also, you can make the median wage in the US without any collage education.
Poverty still exists, but vast inflation of what is considered’a basic standard of living’ hides a great deal of progress. People want to redefine illiteracy to mean being unable to use the internet not by the standards of the past.
So, yes, reasons other than efficiency explain why people aren't working, as well why there are still poor people.