What's bad is that they are often nearly disabled, and if they don't do this, they starve.

No social security for the elderly in Singapore.

If they're not doing anything actually productive, wouldn't it be better to pay them the money and let them spend the time on something they enjoy?

Singapore Cleanliness is a huge mental relief after having to deal with the disgusting mess that various parts of San Francisco are. Keeping this city/state clean is incredibly productive. There is a reason why a story regarding hiring cleaning consultants makes the front page news, and people are fined $15,000 for throwing out cigarette butts - singaporeans take cleanliness very, very seriously.

Cleaning toilets isn't productive labor?

Not if they're already cleaned plenty often enough and it's just busy-work, which was what I understood the parent comment to be claiming.

Without basic income, that's the closest you can get.