My favorite debunking is an old YouTube video called "moon hoax not" where a filmmaker explains that the due to technology limits of the time, faking the multi-hour live broadcasts in slow-motion, which millions of people were watching, would be impossible without there being telltale signs of it being spliced film (the splicing, film grain, etc.). Since slow-mo video (distinct from film; TV broadcasts were video) at the time could not play back more than a few seconds of footage, at most, it would have to be high-speed film played back at normal speed. Assuming you could find or make a high-speed camera fit to task. While the first landing had awful video quality, later missions had much higher quality and the film fakery would be impossible to completely hide. People these days massively overestimate the video (and film) technology that was available in 1969. (IIRC. It's been years since I've last rewatched it.)
Edit: TL;DR: Perfectly faking the multi-hour uninterrupted video broadcasts (i.e., either inventing slow-motion video that can last hours, or perfectly passing off a multi-hour film as video) in slow-motion would have been significantly more difficult than sending humans to the moon with 1969 technology.
Fake moon landing, aliens built the pyramids why do some conspiracy theories insist on robbing humans of their monumental achievements. My guess is that people who create and share conspiracies like those are too dumb to realize that other people have different knowledge than they do.
Also keep in mind that the astronauts communicated with Earth by radio. Anyone with even 1920s radio technology would have figured out that the astronauts weren't broadcasting from the Moon.
We were in the middle of a cold war with the soviets back in the 1960s. Proving the moon landing was fake would have been the propaganda coup of the century for them. What possible reason would they have to stay quiet about that?
The problem with moon landings isn't that they can't be done, it's that they are dangerous as shit, with little reward. You'd get a better deal out of being sent to a remote desert island.