qt_add_qml_module() macro creates a plugin class to load our source modules,
however if we add:
SOURCES include/moduleA/utils/something/header.h

then the generated file will have:
include <header.h>

Which fails to compile because compiler cannot find it.

This can be worked around by target_include_directory(... include/moduleA/utils/something)

But not only this leads to more complex CMake files but also might clash where you might have multiple header.h files in different folders and namespaces.
It really should just include what we give to it.