Central bank digital currencies (CBDCs) are digital payment instruments provided by a central bank as its direct liability, denominated in the sovereign currency. CBDCs are classified into two main variants: “wholesale” CBDCs for limited counterparties mainly used in large-value payments between financial institutions, and “general purpose” CBDCs for a wide range of end-users, such as households and businesses. General purpose CBDCs are regarded as a payment device with high substitutability with both banknotes and bank deposits, as a key financial system infrastructure to enhance the efficiency and functioning of the payment services. General purpose CBDCs can be designed to enhance the separability between payment services and financial intermediation services. General purpose CBDCs are expected to play a key role in revitalizing the financial system by promoting market-based financial intermediation services while securing the stability of the payment system. To that end, the overall design of financial system infrastructures, such as access to central bank services, deposit insurance system, and wholesale payment and settlement system, needs to be comprehensively transformed with due consideration on the feature of financial systems, which is the strong status quo bias due to high degree of institutional complementarity.