Ms. Constitution here, who has devoted her life to its study and implemention, disagrees that our Constitution is the best humans have ever devised. First, many countries do not share our view. The American vs. European view of Freedom of Religion is one that is often discussed here. Our Const'n is inherently a British document, relying on British common law values. Western European countries, and those of places like South Africa, are exemplary.
Our const'n works for us so far in a turbulent history. Jim Crow, Dred Scott, and Korematsu share the stage of infamy. Health care for children was forbidden. The Federalist Papers describe a document and how power is allocated and balanced so no one group has absolute power. Yet the early years, and particularly the Marhsall years, needed a multitude of judicial decisions to flesh out the document. Washington and Jefferson had a very uncivil dispute concerning Washington's order of neutrality in the war against France and England. The document was too vague. Many of the framers believed it would not last twenty five years.
Actual political practice was needed to make it workable. The Framers were in dispute and at each other's throats about what provisions actually meant. It hs worked well for this country on balance. Denmark and the Netherlands must have good const'ns. Since its beginning, the US was a diverse country and had to accomodate many beliefs. People tell me those countries are very homogenous.
I believe Americans were very fortunate that the framers were able to wheel and deal and cover up the politics so ratification would proceed. What impressed me most at the National Const'n Center was a letter from some state legislature that it refused to ratify, no matter what, without a Bill of Rights that was express and part of the const'n. James Madison, Mr. Const'n, believed strongly in civil rights, but felt the matter superluous, that the document as a whole guaranteed rights. The people themselves, state by state, said no ratification without our express rights. Madison, fearful of the ratification process stopping, drafted the Bill of Rights as amendments to the original document. Americans demanded it, not some famous lumiinary like Washington or Franklin, looking down, but the people. The people of "We, the people of the United States America, in order to form a more perfect union."
We certainly have slid in times since.