I personally use a vertical monitor, in Jetbrains that gets me about 130 characters on a line before scrolling, and in VIM it get me about 125. I'll break a long line into shorter lines if they begin to approach the end, but I'm not strict about it. From what's open right now I do have a few lines that get close, and one that goes over. So what? All my coworkers use horizontal monitors and even with gutters and panels open they're not complaining about my line length - and I've not had a complaint about line length since I've started in this industry in 1999. Back then there were no vertical monitors, it was all 4:3 CRTs.

As an interesting note, I now work with the second hard-of-sight developer that I've worked with in my life. They both use normal Jetbrains IDEs, with font sizes and interfaces made huge. Neither of them has ever said a word about my line length. Nor my function length. Nor my long variable and method names. Nor my explicit comments, nor my detailed git commit messages, nor my frequent git commiting, nor my branching preferences, nor my README files, nor my obsessive security practices such as validating types and character length limits on input fields and sanitizing and filtering input and my rejecting of any PR with concatenated outside-data in SQL (even if that outside-data came from the DB itself, for a recent example), and all the other idiosyncrasies that one dev suffers from another.

Line length? Not a problem. Forcing the hard-of-sight dev to indent however _I_ see fit? I wouldn't dream of doing that.

Is there really a value of a max-char rule these days? Editors can scroll, softwrap and usually do neither as screens are large anyway. A max-indent rule makes sense to highlight when you're nested too deep and should refactor, but a long line of code can either be done based on "this looks unusually long" or a formatter that has a set tabwidth.