While Chaum’s vision did fail during its time, now - that ecash can be deployed on top of Bitcoin - it offers new unique use cases not possible with other tech. Instantly confirmed micropayments due to ecash’s bearer instrument qualities is just one example. Of course there are downsides, but it’s important to remember that there are no fool proof solutions in life, only trade offs.

Custodial solutions on top of bitcoin remain custodial and vulnerable.