Your picture of people on welfare seems a bit rosy

Does it? I didn't say it was a good thing.

You think everyone has credit cards?

I don't need the premise that everyone has credit cards to support the conclusion that some people on welfare do. I hear news stories about it.

It is, of course, possible to make GBI, to use a legal term, "non-garnishable" meaning it cannot be collected to satisfy a judgement against a person. But that would make it impossible to use it as collateral for a loan to buy equipment, for example.

But you could set a non-garnishable component that is less than the whole GBI. I am still not seeing a novel problem.