I have to say it is refreshing to see someone actually thinking about things like line length when it comes to how their content is portrayed. To me, this is not just being persnickety, it's about intention. If you want me to resonate with your idea, the more clearly it is communicated (writing and typography) the easier it is for me to get invested.

Look at the simplicity of articles on The New Yorker, for example, which are very long but very readable because there's very little cruft to distract you and the design is so simple. My experience there is almost interchangeable with a "reader view" of the page, a feature that by its very existence should communicate that the modern web has lost its way in thinking about these things.

It's not that every site needs to be minimalist, but if you're writing essays or text of substance, caring about this kind of stuff goes a long way. "Engagement" is not just how long I stick around but the mental investment I put into what's there, and when it comes to writing, less design is often more.