One could argue that custodial wallet providers should be using blinded ledgers aka eCash in their very own interest.
If they don't phsically record who owns what, they can't really be compelled by agencies to hand over that data.
[They may still be forced to shut down their service altogether for all kinds of regulatory reasons, e.g. being classified as Payment Service Provider, which doesn't have a license. But that's a different discussion, and the very same risk exists today - where they still record very user transaction unblinded]