But we don't want to know the running costs; if we did, we'd loose opportunities to cultivate mutually agreeable agreements with private industry leaders and businesses (read: opportunity for grift, backscratching, and socialised losses&costs/privatised profits).
And we'd be forced to work in a competitive work assignment structure; studies (that's been cherry-picked from the get-go) shows civil service works better without such, instead focusing on trimming and specialising core competencies vis-a-vis inclusivity and equityamong clients. (Don't need to translate that, you've been to the DMV, yes?)
Also, from the political angle, your suggestion would mean heightened demand for lowering of taxes, and such populist radicalism is a threat to democracy: since politicians are the guardians and paladins of democracy, anything which diminishes or shrinks their freedom and ability to act is an attack on democracy itself.
(They really do think that way, no sarcasm intended.)
We have the same perverse incentive-structure here, ever since the 1980s/1990s, when neoliberalism and its inbred family of moronic theories got implemented.