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.
Here in NL the amount gets rounded to the nearest multiple of five, so for 1.92 you have to pay 1.90 in cash and 1.93 will become 1.95. This so on average you are not overpaying. Digital payments are always exact.