For many years now KDE has focused on polish, bug fixing and "nice-to-have" improvements rather than major redesigns, and it paid off.
VDG tackled (and tackles) not only design for the desktop itself, but also for KDE applications that had never seen a designer's touch before.
I've been long a KDE user, even through the 4.0 troubles, but also the first to admit that it used to look clunky. Looking at old screenshots is a quick reminder of how far this initiative has taken it.
I love open source and have been running Linux since 1999, but my experience of contributing to both KDE and GNOME is your PRs never go anywhere unless you're part of the inner cabal of maintainers, otherwise any small bugfix or feature goes into bikeshedding mode, and it's the reason I don't contribute any more.
That said, I run KDE now after two decades of GNOME. It's pretty good and has been looking good for a while now.
What's up with the massive amount of chrome used for nothing except new tab/copy/paste buttons? Is it really necessary to take up what could be used for 2+ extra lines of terminal output for a labeled Copy button? Compare it to gnome console, or any other terminal really, and you will get far more terminal output for the size of the window, as it should be.
And it's not just Konsole. So many KDE apps have this same problem. Giant labeled buttons taking up space from the actual content, for things you will never use or have well established keyboard shortcuts already.