How does leo tolstoy contrast the characters of gerasim and ivan ilyich in the death of ivan ilyich?

Ivan Ilyich is the main character of the works "Death of Ivan Ilyich". He is not an unscrupulous villain, he is just a good professional in his field, and deservedly successful move on his career ladder. His main problem is that he believes it is necessary to avoid relationships with people, besides service relationship. But when he fell ill and knew that he is dying, he wants to be regretted by someone, that he had never done for the sake of others.I think that this is what distinguishes the main hero from Gerasim, who did not abandon the dying Ivan Ilyich and tried in every way to help him, in the hope that when he will be dying, someone will do the same for him.