Is it possible to create a normal desktop and mobile 2D game and 3D game on QT and does the speed of C++ remain the same or on QT its speed turns into Python without Numpy? If this is useless or there are better options, what libraries should I use and how do I convert them to a specific platform?

Is it possible to create a normal desktop and mobile 2D game and 3D game on QT and does the speed of C++ remain the same or on QT its speed turns into Python without Numpy? If it is pointless, then what libraries should be used and how should they be converted to a certain platform?