For a castle of playing cards, it is most essential that each card is strong enough, there is no wind and no one pulls out a single card. In practice, these assumptions do not work. As happened in U.S.S.R. and South East Asia. The falling cards take down with themselves, even the steady cards till everything meets dust. The Building Blocks of the Castle.
Money is a symbol.
1.1 Money has replaced barter trade - which was the real thing. Because Governments are ruled by politicians. More often than not, the politicians are neither honest, nor wise. Practical men do not make assumptions which are impractical. You can not assume the Government for ever to be wise and honest.