Citizenship, in any country, is all about privileges, immunities and obligations. Forfeiture of citizenship in the U.S. is a two-step process. First there is renouncement and then relinquishment by the U.S. Only relinquishment with the issuance of a certificate of loss of nationality relieves a renunciant of their obligations to the state.
Anyone who renounces still must file their tax returns, register for selective service, etc ... Only a certificate of loss of nationality issued by the U.S. will relieve a renunciant of their obligations.
So you are in effect saying that the US government owns its citizen-slaves?