The whole point of the "You can't live on £3 a day? For shame" take is not that the rich think they could do better, but that they believe the poor are incapable of managing money so all benefits & charity are by definition wasteful.
Trying to defend people who would rather eat oven chips than boiled spuds by talking about preparation time or kitchen utensils is self-defeating as it's a plea of un-manageability. You're responding to a criticism of attitude with an explanation of structural constraints.
Matthew Parris famously tried to live on benefits for a TV doc in the 80s & failed miserably. This didn't convince viewers that benefits were inadequate, but that someone you would expect to be incompetent because naive (a posh Tory journo turned MP) really was incompetent.
There's a reason why programmes & articles about clever housekeeping are usually the work of the middle classes, & it's the corollary of the fatalism of "prole porn". It's about mentality. Even when they fail to live on benefits, the rich are admired because of their confidence.
