Sure, you don't have to do any of those things, but you'll be seriously disadvantaged if you don't because the games are designed around these mechanics. Maybe it's exaggerated, but on the other hand, as a fan of both Doom and Doom 2016 it seems your response downplays the difference these mechanics and using them to your advantage makes, and I agree with GP that these are substantial differences that fundamentally make the games play differently.

Not in a bad way (well, mostly. I still loathe the weapon/armor/character upgrade part of the game). There's no real mowing or herding like in the more intense levels of Doom and Doom II, but instead we get really intense fights that are cool in a different sense.