What's the Deal With Costco?

I am probably the last American to step inside a Costco. (did I even spell that right?) There has been one in Alaska (in Anchorage) for years, and it is my understanding that everyone is madly in love with it. There is a smaller version of this monstrosity around Alaska called Three Bears--that I understand. I can get good kitty litter there, cheap coffee and now and then some camping gear. Nothing to be overwhelmed about, and probably a good deal if you run a B&B and need bulk stuff.
But the giant Anchorage Costco? No, no, no. I am not understanding it at all. It is a hideous experience to walk in there. Like you are going to have a stroke or seizure. All those giant TV's blaring and people everywhere and giant pallets of who knows what forming towers in a city of tackiness. Clumsy patrons stroll about pushing carts full of Ramen noodles. It is such a confusing experience I couldn't figure out if we were walking in the clothing section or looking at frozen chickens (which by the way weren't even such a good deal).
Do Americans really eat so much that an average family needs like 2 gallons of mayonnaise and 12 jugs of fruit punch at one time? I can't help but think some of that just goes to waste--so there is no real savings.
As we sat dazed and confused eating cheap pizza, I saw what people were buying: canopy's and storage containers, electronic doodads. Hundreds of people roboticly checking out to add clutter and purchase storage solutions for their clutter. Nobody was smiling there. This is the future of consumerism? It reminded me of something out of Wall-e, welcome to Economy!!