Tants are tants. They are not the canned, fluid-filled electrolytic type. This is why tants will last as long as your circuit board, since they have no fluid inside. Electrolytics in most cases will leak after 12-15 years. But electrolytics come in bigger sizes than tants, so you cannot always replace electrolytics with tants.
Perhaps you meant to say that both tant caps and electrolytic caps are "polarized." But that's not always true either.