Why is the USD such a confusing currency?

The dime is 10¢. The nickel is 5¢. The penny is 1¢.

But why is the dime, even though it is the largest denomination of the aforementioned bunch, the smallest? The dime is the smallest in diameter and is the thinnest of all currently circulated US coins. Dimes from 1965 to the present are made out of 75% copper and 25% nickel. The Nickel is 5¢, but is bigger than the dime and has the same 75% copper and 25% nickel composition, but has more material than the dime.

And who uses the penny anyway? Vending machines don't even accept them anymore.

Saturday Morning Musings...