The metamorphosis of Gregor impacts allo the character in the story.
One of this impact is suffered by his father. There's a kind of inverse relationship between the protagonist, Gregor Samsa, and his father. The story's basic plot describes Gregor's overall decline while his father becomes more powerful and more controlling. In a way, it's a typical story of a dysfunctional family — were it not for the bizarre twist that the first line tells us Gregor has transformed into a giant, monstrous bug overnight.
Given his current six-legged condition, however, it's unlikely that Gregor is going to report back to his sales job any time soon. Facing dire straits, his feeble old father suddenly steps up to become the man of the house again.