> Every redesign introduces new (secret) watermarks, patterns that are hard to copy, so it's also a "tech" update. Eventually more and more of the details become public. By now the current banknotes are too well known and I guess the counterfeits are getting too close.

But if I wanted to create counterfeit euro bank notes I could just go with the old ones, no?

Anyway, I think creating new designs just for fun is a good enough reason for me to create new notes.