They do not need the stuff they get but if they don't get something they lose that money.
Edit: So i base my stance on first hand real life experience that says it is the exact opposite of your stance.
Government offices rarely *need* to invest in better computers. They can struggle along with the older ones. however, that doesn't make buying those newer computers wasteful.
I'm not doubting there are examples of waste. However, I have also seen examples of what would, in the private sector, be thought of as investments in productivity.