I like it because if I stick to it, I can have 4 or 5 windows of code open at the same time, spread over one screen. Header files, caller code, and called code all visible at a glance.
If I don't stick to 80-cols, it's actually a roadblock to getting stuff done, and it's really not that hard to keep within the 80 column limit. I don't specifically care about the '80', I just care about what doing that, lets me do in turn.
So my code is pretty much religiously 80-chars max across. YMMV :)
There's also a kind of surprising overlap with tech and visual design theory here. If you are creating even a simple design system it's important to watch your column-defined widths and be conscientious about them.
Through this lens, 80 column width is really liberal and may seem even presumptively so in lots of ways. As a result it can start to feel much less like a relic of olden times, and more like meaningless extra room for mildly-offensive slop, again given how far we've come with theory. Occasionally people will reference design principles as they exist independently of their tech tools and make some changes but it's very rare in tech.
Even more importantly though, the conscious integration of design theory can be used with intent to change the whole scope for the better, and there are ways to manage/leverage any extra breadth more creatively than we currently do in the text editing world. I hope to see editors and language standards move further in this direction in the future.
If I don't stick to 80-cols, it's actually a roadblock to getting stuff done, and it's really not that hard to keep within the 80 column limit. I don't specifically care about the '80', I just care about what doing that, lets me do in turn.
So my code is pretty much religiously 80-chars max across. YMMV :)