As several users have pointed out, the top right of the 3D View suffers from 'buttonitis' - sometimes we have 3 rows of icon buttons here, which makes things very hard to visually separate.
We can improve this by making two small changes:
- Move the viewport gizmo buttons to flow along the right edge
- Slightly change the default theme so the header is more distinct from the 3D View background, making it be more separated:
We could also increase the Y height of the tool settings region:
This adds more separation, and also gives enough space for the tool icons, which currently are cramped: