And in the UK, you vote for your local member of parliament. And the winning party decide who is to be their leader and he/she becomes the Prime Minister.In USA, the "government" works in a very different way than in Germany (or most European countries).
In Germany, you elect the Parliament, and then the majority of the parliament elect the Government, which makes the decisions. So, if a decision of the Government does not pass, it probably means that the Government has lost support of the parliament and this may lead to new elections.
In USA, basically the President is independent of the Parliament, and it is the President that chooses "the government". The parliament does not choose the government, but the parliament passes the laws. And elections happen every two years for parts of the Parliament, and every four years for President. So these two (Parliament, Government) are not connected that much, and both have a lot of power. USA does not have a prime minister, and actually the President is something very different.
In USA, you can have a President from one Party, and the majority of the Parliament from the other Party, which is a situation that does not really make sense in Germany or Italy or most European countries.
So, even the minority leader has a lot of power in USA, while in Germany he practically has no power.
And the PM is a compulsive liar, doesn't give a sh1t about the people and breaks the law.
And the people think he is wonderful and let him get away with anything he likes because he is such a loveable rogue.