GI: I would venture a guess that you have 20/20 vision, corrected or not, and that you're a bit younger than many of the folks who frequent these threads. (You know how it goes, the old folks worked and now they have the resources to use on expensive toys where many of the younger crowd, do not.
Personally, it's a "comfort factor" for me (and I would guess there are others who feel the same way.) To me, if you keep it on the least intrusive setting, High I believe it is, it's only slightly noticeable and I only have to think about focus when I don't see the red edges. Hey, it works for me and the red doesn't bother me in the slightest. Different strokes as my dear, departed buddy used to say... BTW I'm one of the GI subs..excellent vids.
Plus, it's fairly easy to bump the focus grid in manual mode doing something else and with my mediocre near vision, I could easily miss that I bumped it out of focus. I know the focal length of the lens but, it's not a hard and fast barrier so there are times when you and the camera may think you're in focus but you're just a tad off cuz you bumped it. I have certainly had this happen to me which is why I now use peak focus all the time for the old "comfort factor."