It's just a matter of scale. What's impressive to me with the big aircraft is that we can organise thousands(?) of people to build something that big. But when it comes to the principle of flying it's just a bigger version of the fan. If you were to say they used the same amount of energy as a fan then that would be impressive. But they don't, they burn tons of fossil fuels. Geese can fly over the highest mountains too and all they eat is grass.
I mean, actually, it isn't - that's the whole point about scale variance and Reynolds number and why wings that work for insects are not the wings that work for jumbo jets.
