True, but on Jesus was laid the sins of the whole world. So if you use the scapegoat analogy, then Jesus substitutionary atonement reached every sin of every man. The scapegoat was a limited atonement and the lamb was an unlimited atonement.
Joh 1:29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
Joh 1:29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
If you take this verse literally, then all sin would be gone already - we would be living in Eden again. This is obviously not true. There is obviously a limit to the removal of sin in some way. The verse might be saying that it will (in the future) take away every sinners sin but this would be universalism. It could also mean that Christ will remove sin from the world eventually (i.e. when He comes again). This may speak more about a coming world in which sin no longer reigns...
In light of the whole of scripture, I tend more toward the latter interpretation.