>>537016860
That's how episodic stories work. Only the main character is relevant, while the other characters are just pieces in the story to help the main character learn and grow.
MD House as an example:
House meets a new patient > does human experiments on the patient > ends up healing the patient at the last minute > patient is released > we never see them again.
The characters you are pulling are not main characters. They are the new patient that gets introduced each episode.