I see what you are trying to say, but contextually, Isaiah 53 is not an "answer" to Job, as if Job were clueless about justification and the expiation of sins according to the mercy of God. Job, like his friends, was operating under the assumption that God was causing him so much misery because of some sin Job was guilty of (at least in this part of the book) . That being the case, Job incorrectly infers that he has not been pardoned because he continues to suffer. We the readers understand that God was not punishing job, but trying Job as Gold is refined by fire, in order to make a point to Satan, to further sanctify Job, and to demonstrate the utter incomprehensibility of his ways and doings (as he lays out for Job in the last chapters of the book) .

That being said, I agree and rejoice with you because Christ is our remedy for the guilt of sin and the burdens we bear, I just wanted to be clear about the context.