During their first Campfire Chat livestream, Blizzard has announced changes coming to Nightmare Dungeons in Diablo 4 before the launch of Season 1 to make them more attractive than regular dungeons for endgame.
Campfire Chat Summary Nightmare Dungeons and Sigils
Here are all the changes coming to Nightmare Dungeons before the launch of Diablo 4’s Season 1:
Nightmare Dungeons will reward more experience to make them superior to the regular dungeon farm.