That is true of absolutely every form of custodial Bitcoin, not just ecash. They are all IOUs. However, I wouldn't say "you might as well use Zcash" or some other shitcoin, because at least you still have the ability to interact with the Bitcoin network through your custodian. Self-custody is alwa...

Callle and the Cashu folks are getting very close to an eCash mint that can’t rug ya, there’s hope on this front soon I think.