I think it's important to separate the organization of the US government from the politics of the US government. The office of management and budget for example provides a lot of oversight. There are a lot of eyes on every dolor spent by the government and many internal and external watchdogs.

That said, the high level goals are clearly up for debate. People who feel the EPA or Social Security Administration needs to be dismantled don't really care about how efficient it is internally. Also many things are internally imposed such as the SS being is prevented by law from investing in anything except government bonds which is arguably a huge issue, but that's outside of pure graft that is pervasive in much of the world.

PS: Anyway, my point was as bad as people think the US government is there are many far worse examples.