Its due to the fast falling cost of fake. Today, of course, its much easier to fake 50 or so hours of footage to look like going to the moon.

But back in 1969, it was way easier to just go to the damn moon than it would have been to fake the video sent back.

Even in Kubrik's 2001, there was no effort at all to film, say, even what walking looks like on the moon--even in the shots which putatively happen on the moon--even in the shots which happen indoors on the moon! It just would have been too expensive. This in a film in which they went all-out to create awesome special effects.