Why are trash mobs so tanky and maps so big?!

I am rotating the same 3 skills over and over for what seems like over 30 minutes just to go through a zone in the campaign. I cannot believe how dull this is. I can't even watch tv while doing it because of enemies having on death effects and chaos damage that is way overtuned.

Ideally if gameplay is short and engaging or long and casual it's okay, but this is neither. I beg anyone reading this to either make the maps smaller or make the mobs less tanky. I do like the enemy design as there is engaging mechanics to them! I can be going through the area and realize there is a certain enemy, and I have to play a certain way and that is nice!