Lovely money

A Bulgarian banknote - 20 leva GOLD Series 1885
Lots of handsome Bulgarian paper money from a huge private collection of old bank notes, bonds and so on. Bank note design is a fascinating collision of authenticity (not a forgery), accountability (‘promise to pay’) and aesthetics (National pride, solidity, ‘bankability’, history). How will a nation communicate these values once physical currencies are history and States lose their monopoly over their production?