A title banner could add to the identity of the page, like here https://www.gimp.org/ , maybe replacing the purple picture with a presentation of different designs, showcasing them and showing their coherence (color themes), explicitness (icons), intuitiveness (widgets), … . Several things can be done to show the coherence of the designs (i.e.: https://snwh.org/suru , these pages look interesting too : material.io design /develop /tools /…/the-color-system.html and here for a background video : https://www.scandit.com/).

I'd suggest that the homepage is a showcase for KDE's design (colors, icons, graphical style, …) with information on the guidelines of each item and links to more information and the sources. And a news section to show what's happening.
(That's what I was looking for as I went on that page the first time.)