if you have to ask who this is for, it's not for you.
just how professional athletes are capable of super human feats, their footwear and attire matters just so they can shave off milliseconds.
the same applies to professional gamers. they are extremely good at what they do, and one shouldn't confuse someone who is good at games that plays on their down time versus those who do it professionally for a living. their entire day revolves around sharpening their skills, just like an athlete. so the mouse they use, the keyboard they use, the monitor all matters. resolution isn't as important to them, and there is an optimal screen size so their eyes move less. all professional gamers turn down all graphics and effects to maximize framerate and minimize any on screen distraction. this isn't for immersion. it's for a practical use to shave off milliseconds.
again, not for you.