You touch on a fair point that yeah, we don't want to go too far and fit code into a narrow viewport at absolutely any cost. But applied wisely, a little judicious indentation would go a long way.

I don't think zooming is a good general solution, since ultimately it makes the code harder to read.

Well, you're right in that it's a bit more than just "poor knowledge sharing". But I'd say it's more specific than unintuitive code that requires knowledge sharing, too - it's code that is unintuitive primarily because its main reviewers are blind to the exactly how unintuitive it is, and thus a vicious circle persists. We can see this in the author's recommendation to have such code be reviewed by newcomers as well in order to break the loop.