I hear and understand your point. It is not purely a social construct. But how much available farmland to allocate to grow food from the available farmland becomes a political issue. Pricing, distribution... same deal.
And considering our (humanity's) food production outmatches our total food calorie/nutrition requirements... any argument using food as an example for scarcity indicates that you may be working with incorrect, or outdated information.
And Is "money" a social construct, or is there 'natural' money, some platonic ideal from which all other instantiations of money arise? I'm betting on the former.
> It is not purely a social construct.
What else is involved? Despite the inane ramblings of the parent comment, scarcity isn't actually a factor. Allocation occurs because of scarcity. Without scarcity, there is no such thing as allocation. It is the reason for why resource allocation exists entirely a social construct.