There certainly doesn't seem to be any benefits for Gregor to have turned into a bug in Franz Kafka's "The Metamorphosis." He dies. He also suffers alienation, disrespect, and neglect from his family, the chief clerk from where he works, and the lodgers. For a time, he does adapt to being a bug and enjoys climbing on walls, etc., but this doesn't last long. Gregor is a victim, although of what no one is sure.
The story opens:
When Gregor Samsa woke up one morning from unsettling dreams, he found himself changed in his bed into a monstrous vermin.
There is no explanation as to why he was changed. This leads many commentators to view the fictional world in the story as absurd, in the literary sense. Is happenstance at work? Chance? It would seem so.
Concerning his family, they do get jobs to support themselves and seem to be ready to cope with having to work by the end of the story, but I see them mostly as having been exposed by Gregor's transformation. Other editors may disagree.
Why he turned into a bug is not entriely clear. The Russian word that is used has no direct English equivalent but the word "bug" is quite close. The only fantastic element present in The Metamorphosis is its famous opening sentence. After that unexplained event, the subsequent action unfolds in a bizarrely realistic fashion. Perhaps the strangest detail of all is Gregor’s matter-of-fact acceptance of his transformation into a monstrously large bug. He never wonders why or how he has been changed from a young man into a bug.
It is ironic that only after Gregor does, does his family benefit. One of the strangest features of The Metamorphosis is its closing paragraph. Having lost their only son, the Samsas undergo a quiet transformation into a secure and loving family. The final image is quite unexpected. The parents notice Grete becoming “more vivacious.” In spite of all their recent troubles, “she had blossomed into a pretty and shapely girl.” It is time, they decide, “to find her a good husband.” Immediately after Gregor’s unceremonious funeral, they are already planning a marriage. At least one critic has claimed that the title, The Metamorphosis, refers to Grete rather than Gregor; she has been transformed from a girl into a young woman. Her transformation brings the promise of new life while Gregor’s brought only death.