A good example of how people would react is "the Truman Show". On this movie, the government has too many control on Truman. His life is perfect, but he starts noticing he cant even travel to other places for strange reasons. Later, Truman discovers his government controls him and is always watching Truman! After this, Truman starts rebelling, and tries to escape this world he lives in where he has no freedom of traveling or even going to some places. And after many years of his life of him being manipulated, he does what every human would do; He fought for his freedom and broke free!
Some last ideas of why governments need to keep freedom is because people need something to live for. Without freedom people wouldn't have any goals to try and reach and life, along with the whole world itself, would be just... Sad.