A discussion with a friend covered the point that it may usually be better for someone to be doing paid work, however menial, and how ever ineffectively/inefficiently than not working at all. Well, never say never, but ... no, never.
The tests should be:
Is there a direct social benefit from the work involved being done? That is, is a real human need being met. (Just giving someone a job is not meeting a real human need.)
Is doing this work sustainable - does it account for our finite planet?
Can it it be automated (completely or partly). If so, automate it in whole or part.
We are left therefore, with work that only humans can do, that is truly necessary and environmentally sustainable. That work needs to be fairly shared out between those who are capable of doing it.
Those who are not capable of contributing to this work should not be penalised. There is nothing they can do and we cannot morally penalise people for existing.