One nitpick is that Black Mirror is usually dystopian in its view of technology but there has been more than 1 happy ending. The author probably only has San Junipero fresh in their mind.
I don't know how one could classify USS Callister and Black Museum as having happy endings! The fates of the bad guys in those episodes are so horrible they still haunt me. Doesn't make it any better that they are bad guys!
One nitpick is that Black Mirror is usually dystopian in its view of technology but there has been more than 1 happy ending. The author probably only has San Junipero fresh in their mind.
https://screenrant.com/black-mirror-happy-ending-episodes/