They’re not worth anything, never were but even less through the years with inflation.
If a store wants to sell something for 99 cent, they can either just take 1€ or 95 cent.
Maybe even 5 cent pieces? But that would be a bit radical.
I am a bit annoyed that easy ideas like this are never discussed in politics, or wherever. It would make our lives just a little bit easier, and having them achieves NOTHING.
The way it works is you would just do one transaction to a wallet on the chip in the coin when the coin is minted. The chip is designed so that you can never release the funds on its wallet without essentially destroying the chip. There is no way to simply duplicate the cryptographic data from one of these chips to another. There’s a better explanation available on the OpenDime website.