The research argues that CBDCs are operationally unique because their adoption dynamics are endogenous to a central bank's own design parameters, such as holding limits and remuneration policies. It analyses the reserve drain caused by CBDC adoption using the Eurosystem as a primary case study and provides comparative analysis of the e-CNY (China), DREX (Brazil), and the digital ruble (Russia). The authors conclude that CBDC design choices, including onboarding architecture and remuneration, must be aligned with existing monetary policy frameworks to ensure compatibility and effective liquidity management.