Everyone in the world believes that the sky is blue including all the people who lie, and so if all lairs are telling us that the sky is blue then that must mean that the sky is purple. That's flat earther logic.
I do believe that we are lied to by the government, but the thing about NASA is that they can't really lie about space travel because they are not very secretive about their rockets. In order for rocket launches to be faked, everyone involved with building and launching the rockets and anyone observing the construction of a rocket has to be in on the conspiracy, which is literally millions of people including tens of thousands of private contractors. Even if they just built real rockets and crashed them that would mean that everyone who designed, debugged, tested, or even looked at the launch program would have to be in on the conspiracy and that is still well over 1,000 people. Now that's just NASA, for all space travel to be fake it would require literally every space agency, both private and government funded, would have to be in on it including ESA, JPL, Virgin Galactic, Blue Origin, SpaceX, and
dozens more. That's a lot of conspirators. Isn't a conspiracy supposed to let as few people in on it as possible?