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.
Finland: Price totals are rounded to 5 cents at the checkout but the smaller money is valid and you can generally use them, unless a shop specifically informs that they don’t accept them.