I think the key to understanding the allure is by extending your line of reasoning even further.
Why play piano? There are plenty of recordings of people who play better than I ever will.
Why play chess? I will never be able to beat my computer anyway.
Why paint portraits? I will never be as good as Rembrandt, and my camera is infinitely better anyway.
I think the point of the activity is not "I will take the best picture of this plane/the moon that anyone has ever taken". Rather, it's "I will take the best picture that I ever took".
a) it's not hard, it just requires a long focal length.
b) it's not a creative act. The moon drowns out anything else, so it ends up being just a picture of an orb surrounded by black.
Piano is extremely challenging, and playing something well gives you that feeling of having overcome a worthwhile challenge.
Chess is likewise a battle of self-improvement.
Same with painting.
Moon photography? There's zero creativity involved, it's just about whether you've gone out and bought that 150-600 zoom you've been eyeing.
Why play piano? There are plenty of recordings of people who play better than I ever will.
Why play chess? I will never be able to beat my computer anyway.
Why paint portraits? I will never be as good as Rembrandt, and my camera is infinitely better anyway.
I think the point of the activity is not "I will take the best picture of this plane/the moon that anyone has ever taken". Rather, it's "I will take the best picture that I ever took".