The American constitution was designed by the founders to ensure that power is shared by many people in different parts of the government on the principle of "checks and balances". This concept has turned out to be a nightmare. The government is grid-locked. Nothing can be decided unless there is "compromise". In many cases, the compromise is achieved through some form of "corruption".
The legislator will vote for the bill if he or his constituency gets some benefit. Or the people in the executive government will take some executive decisions if somebody that they like is benefited in some way. In some cases, the benefit is given in some hideous way and a secret way to the people who make the decision.
This is how America, in spite of being a democracy, has evolved into a corrupt form of government. To make matters worse, the corruption has now gone to the next level, where the people with the money can make large donations to fund the election of their legislators, presidents and governors who will make decisions favorable to their donors.
The system in other countries is not working as well. In many of these countries, the power is concentrated within a small number of strong leaders. They make most of the big decisions. The other people in the government are "yes-men".
The big decisions were made in a close circle, within the leader or his family or a small circle of cronies. The public does not know what how the decisions were made and who really benefited from the decisions. Usually, some members of the families or the close circles of cronies benefited most from the decisions. The people pay the price.
There is lack of transparency. The media is controlled and is not able to expose the hidden corruption.
Both extremes are bad. We need people in government who have high ethical principles and have the passion to serve the people, and not for their personal greed and personal gain.