There is the possibility to enable and disable feature like here: https://github.com/qt/qt3d/blob/dev/src/CMakeLists.txt#L6

But add_subdirectory(plugins/sceneparsers) -> add_subdirectory(gltf) adds a hard dependency on Qt::3DExtras. And Qt::3DExtras depends on the input, logic and render feature so having the features here is useless because you have to enable them anyway

The features are currently used by vcpkg here, but I am totally fine with removing them and making them a hard requirement (actually I don't care if you fix or remove them, but the current state is broken)