The modern argument for lower-line-lengths is the ability for more screens+fonts+UIs to display two blocks of code side-by-side. Somewhere between 80 and 120, you start to force many UIs to wrap. Adding to the subjectivity, approx nobody cares about one line of long code out of 100,000 -- so what percent of code-that-wraps is too much?

To avoid dying on that hill, many eng leads just throw up their hands and give into the 80-column folks, even if it's less productive for everybody else.

The beauty of gofmt and black is that formatting can become a commit hook, so no human wastes time cutting lines manually like some early 20th century typesetter.