I think discussion on the perfect limit on public forum is non-sense. It might be slightly less non-sense to discuss it with your team, but even that I think it is bike-shredding most of the time, unless the entire team for some reason (like they share the same equipment setup and happen to have same preference) overwhelmingly share the sentiment.
It kind of sounds like you're promoting your own setup.
The funny thing I see the most is that people with these crazy widescreen monitors still maximize just one window, with just one file open. Not sure why, maybe for focus?
On my screen with 1920x1080, 2 side-by-side panels can fit 100 chars, but only if the sidebar is hidden (project layout, list of open files, that kind of stuff).
On my laptop, 2 side-by-side files won't fit if they exceed 90 chars.
I just don't want to concede to those devs who use a single editor pane with an ultrawide monitor, and believe that everybody must work like they do.