[crazygringo]

> information density (function) should always win out

No. Clarity should always win out.

Spacing serves the important purpose of creating an information hierarchy so it's intuitively visible at a glance how things group into larger things. The higher the level, the higher the spacing.

This is why there's more space between words than between letters, between lines than between words, and between paragraphs than between lines. And similarly how there's more UX whitespace between a list and the toolbar buttons above it than there is between list items, and then even more space than that between the main content area and left bar.

Seeing more stuff isn't useful if you can't tell at an intuitive glance which commit a line belongs to, because there's no extra separation between commits.

[zozbot234]

Information hierarchy is relative. You can totally allow for it within a denser layout, in fact traditional dense GUI's and text layouts pay a lot of attention to proper hierarchy. Where whitespace seems to be inescapable is for separating active elements of a layout, to avoid unintended touches.

[senttoschool]

You should try UI design. Open Sketch or Figma. Start putting buttons and boxes together. You'll quickly realize that having adequate spacing is absolutely a must. Everything just looks awful without enough spacing.

Usually, the biggest problem a piece of software has is adoption. People are far less likely to adopt your software if the first time they look at it, it looks like a huge complex mess. The sales people certainly won't want to present software like that to potential customers.