buffalo nickel . The words "One Cent" are the highest point on the coin. This means they will wear off the fastest, making the coin's denomination unknown. The original buffalo nickel had the words"five cents" as the highest point on the reverse of the coin. The problem was corrected during the first year of mintage.
I don't expect the Shield cent's problem to be corrected. Wear on the words "One cent" will be prevented by the fact that cents see little circulation. When people get them in change, they throw them in drawers and forget about them. If they circulated as much as quarters, the denomination would quickly wear off.
Perhaps the nature of "One Cent" is an admission by the mint that the cent is a coin that has outlived its usefulness.