That's the QtQuick 2D renderer. They mostly use that on devices without a decent 3D GPU.
That was also Qt 5.7. With Qt 6, QtQuick itself is part of QtGui now. It is available under LGPLv3 and additionally under GPLv2, GPLv3, Qt for Device Creation Professional (Pro) and Qt for Device Creation Enterprise (Enterprise).
But the embedded companies I've worked with tend to avoid LGPLv3 because of the anti tivoisation clause. (To let the end users swap out the Qt libraries on your devices).
That was also Qt 5.7. With Qt 6, QtQuick itself is part of QtGui now. It is available under LGPLv3 and additionally under GPLv2, GPLv3, Qt for Device Creation Professional (Pro) and Qt for Device Creation Enterprise (Enterprise).
But the embedded companies I've worked with tend to avoid LGPLv3 because of the anti tivoisation clause. (To let the end users swap out the Qt libraries on your devices).