I think there's some fun to be had with this. It does amuse me that people trot out the 'special effects' argument, suggesting that movie technology could have been used to fake it.
As a big fan of that era's sci-fi classics, I know purely from a spectator's point of view that it's a laughable suggestion with both TV and film getting lots of stuff either wrong or just plain silly looking. Don't get me started on the US news network simulations used to compensate for the lack of TV coverage.
Even films made some time after Apollo were very poor by modern standards. Superman and James Bond's lunar sequences are laughably bad.
Do people have any favourite examples?
Space 1999
Six to eight years after Apollo 11, with significant advances in special effects, access to hours and hours of lunar footage, and thousands of high quality still photos, they STILL couldn't get most of the important stuff right; the lunar surface and mountains, the behaviour of dust in a vacuum under 1/6th G and the appearance of astronauts working under low gravity; and in a TV series that was set on the moon!!!
IMO, this shows that it was simply not possible to fake the lunar landing and surface walks in a studio in the 1960s and 70s.
EDIT: the special effect supervisor on this was Brian Johnson. His resume included
2001: A Space Odyssey (assistant, uncredited),
Alien (SFX supervisor) and what I consider to be the best of the six
Star Wars movies.
The Empire Strikes Back (SFX supervisor)