Well, every other country in the world manages to print notes of different denominations in different sizes and colours so the visually-impaired have no difficulties using them. It also makes it easy to tell at a glance how much money you have in your wallet, and it's much harder to make mistakes. But Americans seem to have stubbornly resisted that innovation too.
Is there any thread that you can't use as a dig against Americans, FD? Damn the envy is thick over there.