If most of us want our government to fulfill a particular role, and that does not violate the Constitution, then it should fulfill that role. Even if it does violate the Constitution, we have a means to amend the Constitution if enough of us want to do that.
It may take a while to get laws changed, and even longer to get the Constitution changed, but it has worked pretty well so far compared to other systems of government.
If you want "efficient government", then we need to find a strong benevolent dictator like the Sultan of Oman to run everything.
