Do Americans not put butter on their sandwiches?

I was listening to a podcast and they were discussing how they find it weird, Americans don't put butter on their sandwiches.

Is that true? Aren't your sandwiches dry?

Edit 1: Who knew you would all be so passionate about sandwiches

Edit 2: it's weird to me that you call a burger a sandwich. A burger is a burger, not a sandwich

Edit 3: What savage is putting olive oil on the bread instead of butter?

Edit 4: do you not check your bread for mold? I know there is so much sugar and preservatives in (some) of your bread, does it not go moldy? I check out of habit before making a sandwich

Edit 5: OK last edit. You're really calling us "fatass" for putting butter on sandwiches and then following it up with 'I put Mayo on my sandwiches' like that's healthier