It's an implementation of an old recommendation to never have more than 80 characters per line, ostensibly to limit horizontal eye movement but mostly stemming from legacy 80-character terminals and punch cards.
The value of that recommendation is rather dubious considering today's high-resolution displays that allow for smaller font sizes. 80 readable characters at 768p are not the same as 80 readable characters at 4K.
The value of that recommendation is rather dubious considering today's high-resolution displays that allow for smaller font sizes. 80 readable characters at 768p are not the same as 80 readable characters at 4K.