QtQuick3D isn't only available via the commercial license. It's available under the GPLv3 too. And https://kde.org/community/whatiskde/kdefreeqtfoundation/ http

QtQuick3D isn't only available via the commercial license. It's available under the GPLv3 too. And https://kde.org/community/whatiskde/kdefreeqtfoundation/ https://kde.org/community/whatiskde/kdefreeqtfoundation/ means that they can never make any add-ons that are only available via the commercial license (on penalty of triggering the failsafe that would destroy the entirety of their existing sources of revenue).