Let that be a lesson to the US, seeking government efficiency is a non-goal. Good, well-funded public services make productive citizens and a strong economy. Austerity leads to a dead country.
Most Western European nations have a government expenditure as a percentage of GDP of roughly 50%; half the economy is government.
Singapore, a famously productive country, is around 15%.
You really went out of your way to pick the only "country" you could find with both low government spending and high quality of life, despite the data proving a strong correlation between these two in actual countries. Wow.
No worries, they're busy speed-running it to its conclusion..
An "economy" is just a measure of the overall movement of money. If the bulk of that spending is internal, then that is contributing to the economy. Govt workers are consumers, local companies are providing goods to govt etc.
USaid for example spent a lot of money on food. And a lot of that was purchased from US farmers. Killing USaid "saves a lot of money" but also costs a lot of producers their income.
As long as the bulk of spending is local, govt spending is an excellent way of keeping money moving.