The only real way is for individual private companies specialising in one particular aspect of an aircraft ie radar components. That company refines and SELLS PROFITABLY radar GAN modules. Not the whole radar just the GAN modules made with the highest efficiency and COMPETETIVE COST to supply to other radar makers. Its specialization is just GAN . Everything to do with GAN .agree, its a non starter to develop everything in house and delay the project by another 10-15 years. We tried to develop everything for Tejas and we know how that turned out.
Others then integrate these wide range of specialist products into a aircraft that then possess the best of all the different aspects of a plane.
Anyone that tries to do everything inhouse ends up as HAL.
A broken barely functioning company , always late , always way above initial costings, and a product that is disappointing at best.