"The Eastern Rites still administer confirmation as it supposed to be administered, to adults and infants immediately after baptism. Confirmation is one of the sacraments of initiation."
As does Holy Orthodoxy.
Paul always insisted on "completing" baptism by confirming those he preached to, "as they had not yet received the Holy Spirit," meaning the fullness of the Spirit as expressed through Confirmation.
The new Rite of Christian Initiation for adults teaches the fullness of the initiation rites as we are about to experience at the Easter Vigil.
I can see why our bishops do what they do, as we have no "rites of passage" in the American culture (unless drinking one's first beer qualifies). Still, administering the sacrament of Confirmation at age 17 dilutes the meaning of the sacrament; it becomes a way to coerce parents to make sure their kids keep coming to religious ed classes.