The “Criticism and risks of the digital euro” section on Wikipedia outlines my concerns about such a system pretty well.

Unless they are going to implement a cryptocurrency with centralized minting (essentially giving themselves both as much and as little control over the digital currency as they have over physically printed money), it doesn’t seem that much different from what we have already. Just because it’s going to be a new system, doesn’t really mean it not going to have issues with false-positives suspending regular transactions or fees that are higher than they need to be.