Doom Eternal can get really heated, and I’m not just talking about the denizens of Hell here.
On higher difficulty settings things can spiral out of control, so it’s imperative that you use the entire arena and explore all of it: even a death can be beneficial as long as it grants you knowledge of the battlefield (unless you’re playing the permadeath mode, then you’re screwed).
Source: Destructoid Doom Eternal guide: You need to use the whole arena to survive on higher difficulties