Great question, here's the way I look at it: 1. Print design has honed in on this approach with remarkably consistency. I did a study of various publications (

Great question, here's the way I look at it: 1. Print design has honed in on this approach with remarkably consistency. I did a study of various publications (e.g., magazines and books) when I was first learning about vertical rhythm and found that practically every publication I looked at implements vertical rhythm. But this is also a bit of red herring, because in print publications, you almost always have multiple columns, and multiple columns have additional issues when vertical rhythm isn't implemented because it means body and headline copy won't be along the same baseline (an issue that isn't present in a single column text for example). But I still find it remarkable how consistently the rules are implemented in print design, given how little people talk about it in web design. 2. For me personally, before I learned about vertical rhythm (which I learned along with grids, and typographic proportion), I found everything I designed always felt sloppy in some undefinable way. Now that I use these strategies I no longer see that sloppiness in my designs. Purely subjective, but what I'm trying to say is that to me these systems solved a problem in my designs that I wasn't able to solve just "by eye". Neither of those are objective of course, but those are just the ways I personally have been convinced they're "the right way".