I don’t like when people compare Black Mirror to the Twilight Zone cause upon rewatching it the Twilight Zone had a lot of episodes with happy, if not bittersweet, endings.
like there are several episodes of The Twilight Zone where the message is “death is inevitable” (One For the Angels, The Hitchhiker, Nothing In The Dark off the top of my head) but it’s not, like, a disheartening or pessimistic message. Death is always portrayed as a calm man who isn’t supposed to evoke any horror or fear. In the Hitchhiker he’s the one she’s trying to flee, but he’s not a monster or anything. He’s just patiently waiting for her to accept her death.