"Right" is a bit of a stretch. Manicured screenshots are a tiny subset of theming requirements. People went to great lengths to theme GTK because, for the longest time, Adwaita was truly atrocious, with poor contrast in inactive windows and retina-burning acid active colours.
KDE solved 99% of the theming requirements by just allowing color customisation and shipping with a default theme that doesn't suck too badly.
KDE solved 99% of the theming requirements by just allowing color customisation and shipping with a default theme that doesn't suck too badly.