Self-custody is the part of Bitcoin culture where trust is most explicit — hardware wallets, multisig custody and cold-storage services compete on whether customers believe their coins are safe with them. Storage-vocabulary domains suit cold-storage providers, multisig custody platforms and hardware-wallet brands serving the self-custody audience.
Self-custody is where Bitcoin culture is most explicit, and the brand layer around it is still forming. Hardware manufacturers and custody services compete almost entirely on trust signalling, and the vocabulary available to signal it — wallet, safe, lock, guard, store, custodian — is short and almost entirely English.
A storage brand carries an unusual burden: the name has to sound safe without sounding like a bank, and familiar without sounding generic. That narrow band is why the good strings in this category were taken early.