most prominently it's reflected in the character of Cooper himself. He is exactly representing this pioneering attitude as one of the few people who are not ready to give up humanity's progress and accustom himself to the situation rather than actively trying to advance beyond it, as also reflected in his dialogue to Donald after the meeting with the teachers:

It's like we've forgotten who we are, Donald. Explorers, pioneers, not caretakers...Well, we used to look up in the sky and wonder at our place in the stars. Now we just look down and worry about our place in the dirt.

This is also reinforced by the screenwriters Christopher and Jonathan Nolan themselves in an interview with Jordan Goldberg, as printed in Interstellar: The Complete Screenplay with Selected Storyboards where they even go as far as setting it in relation to our current attitude towards space exploration, putting the movie as a parable to remotivate humanity's drive towards the stars (emphasis mine):

JN ...I wanted to do something that reflected what I thought was the current state of human ambition. Which it is to say we congratulate ourselves every day on living in this spectacular moment of technological advancement and progress [...] but we're not going into space. Measured purely by altitude, the human race peaked fifty years ago. //

JN ...the safe bet was in a million years that alien anthropologists would come to Earth and they would find a stick with a piece of polyester on the moon, and they would say, 'Wow, they almost made it. They got that far.' So, you wash away all the day-to-day stuff that we get caught up in. [...] That drive to get out, to explore the universe, will be the residue that's left behind. Armstrong will be the person that people talk about.

Which brings us back to the "faked" moonlandings. They are a perfect way to highlight this contrast between Cooper and the society he lives in, seeing how the Apollo missions were the pinnacle of human-led space exploration and to this day remain a signpost achievement in this regard. For humanity to ignore and deny that achievement, they ignore and inhibit their own progress.