Blizzard just dumped buckets of demons on Diablo 4 to make the endgame grind way less miserable

pcgamer.com:

Diablo 4's patch 1.1.1, which dropped this week, included a ton of welcome changes to its weakest classes and builds, but one wide-reaching change has started to improve the action RPG for everyone.

In the patch notes, it's only one line: «We are increasing monster density in Nightmare Dungeons and Helltides.» The developers showed a visual comparison between an old and new Nightmare Dungeon on a recent Campfire Chat stream, but Diablo 4 has far too many dungeons and Helltide locations to be able to trust one example. We needed to wait for someone to do the math.

It turns out, the monster density increase might be the most important change in the patch, smoothing out the painful slog that is trying to climb past level 50. Once you reach World Tier 3 and above, Diablo 4 hits the brakes. Loot drops just as much as it did before, but that experience bar at the bottom of the screen moves slower than a line at the DMV.

Nightmare Dungeons and Helltides are the primary way to level up in Diablo 4's endgame and now they're overflowing with demons. Nightmare Dungeons have seen a roughly 50% increase in enemies, which results in a considerable boost in total XP gained for every run, and Helltides are no longer a waste of time if you're trying to find specific gear.

Diablo 4 content creator Raxxanterax spent the last few days running through Nightmare Dungeons to see how beneficial the changes are for leveling up. He calculated the time it took to blast through each dungeon and how much XP he gained to produce a tier list of the best Nightmare Dungeons to run for leveling up. His tests found Domhainne Tunnels is among the best Nightmare Dungeons for XP per hour.  

But it's more than just XP that makes the density increase great.