> 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.

That's not the case, though. You might be somewhat disadvantaged, but not seriously.

On my first playthrough on normal difficulty I essentially only used the Super Shotgun. I can't remember using the Chainsaw for ammo, but I did use the BFG a handful of times.

The developers have even said that a goal of theirs was to make this "playstyle" (using only the SS) less viable in Doom Eternal, because it was too simple and powerful. It might have been on a NoClip podcast, I can't remember OTOH.

I've not played Eternal yet, I'm waiting for updated nvidia drivers to hit my distributions repositories.