It’s easy to understand why people would be skeptical. Skeptics often point to the motive for wanting to fake the whole thing. The race to the moon was part of the Space Race, during a particularly tense time during the Cold War. The United States and Soviet Union were battling it out to get there first. Skeptics say the United States would have wanted to fake it to show they won the Space Race even if they knew it actually wasn’t possible to go. The Soviet Union had epically failed to ever get even near the moon, so they argue it seems suspicious that the United States able to land men safely on the moon six times in 3 and a half years, yet never do so since. Was this just a publicity stunt, faked in order to strongly discourage the Soviet Union and give the United States a huge advantage in the Cold War while saving its lots of money?
But how could this hoax be pulled off? Skeptics argue the technology did exist to recreate a fake mooning landing in a film studio. Sure, they argue the astronauts really did take off into space, but they likely just orbited the earth for several days before landing back on Earth, while faked footage was distributed to the masses.