The difference is that being saved from the wrath of God, having salvation now and in the future, etc. are all Biblical revelations from the Apostles. The rosary is made up from whole cloth.
Not the way Protestants practice it. Calling a practice by the same name as a Biblical concept is what cults are all about.
Furthermore, presuming something is not valid and authoritative simply because it is not cited in Scripture is similarly erroneous (i.e. Trinitarian theology)
Actually, the rosary is made up from the common people entreating the Throne of Heaven for a simple, tangible devotion to that Throne.
That it took the form of a devotion to Mary seems to be a curiosity that will only be revealed with the beatific vision.