That energy cost is intrinsic to aluminum casting. If you’re recycling aluminum like this, you are going to have that cost anyway - even if you use a different technique like rolling or pressing or extrusion to form the final pieces (that said I bet induction heating aluminum scrap to melting point is a lot less efficient than heating an ingot)

Mass production is not only about energy efficiency. It is also about material efficiency and time efficiency. People want stuff NOW. Each process has its advantages. 3d printing can do stuff that mass fabrication techniques can't.