Is there a name for this?
Eg. Jintai or Shinsekai Yori.
Not looking for a recommendation, just the name of a genre.
There's セカイ系, but that really describes the style (i.e. story taking a back-seat to worldbuilding) of Jinrui and SSY, rather than their setting.
i.e. Hoshi no Koe would be セカイ系, whereas Fallout would not.