That’s as naive as trying to convince a 5-year-old that there’s no Santa Claus by arguing that reindeers are physically incapable of flight no matter how hard they flap their legs.

A slightly better argument is this: you cannot fake transmissions from the moon. I mean, it’s far too easy to determine from were a transmission (ie the images we saw live of the moon walk and the radio communications) comes from by simply triangulating the position based on signal strength and direction. If those transmissions had come from anywhere other than the moon, every scientist and amateur radio aficionado in the planet would have known it. So you’d have needed everyone, even the Russians, to be in on the scam for it to have worked.