I was wondering the same thing when I was watching it. Everyone else goes back to their normal lives. Jack is a surgeon, Clarie comes to US to give her baby for adoption, Kate is running away from police, Hurley is rich, Charlie is an addict, etc etc.
Didn’t Miles communicate with the dead? That was kind of his job before he was on the island. I don’t recall what season, but in one of the episode an African lady called him to her house to communicate with a dead person.
Something is not making sense here, did miles quit his job to pursue an awesome career of communicating with the deceased?