Repair-It

One of at least two assumptions in your question is that the purpose of a system of government is to "get things done". I disagree with that assumption. IMHO the purpose of government is to get out of the way, let individuals get done what they want to get done, with as little interference as possible that is compatible with maximum freedom for everyone. So in most cases improvement in government comes with less government, reducing the sphere of the state and increasing the sphere of the individual.

Remember, the hard part of government is not getting things done. Stalin got things done. Pol Pot got things done. Hitler got things done. The hard part is reconciling the different opinions of what should be done. It is better to let individuals decide what they want to do, with their own money, than to fund a large centralized state authority to "get things done" in an expeditious way.

“I am for doing good to the poor, but...I think the best way of doing good to the poor, is not making them easy in poverty, but leading or driving them out of it. I observed...that the more public provisions were made for the poor, the less they provided for themselves, and of course became poorer. And, on the contrary, the less was done for them, the more they did for themselves, and became richer.”

― Benjamin Franklin