The most well known thing about Musk besides being an asshat, is that his timelines are almost always imaginary. He is not building fabs on the Moon in "just a few years".

He doesn't have to build them to sell them. FSD has been sold for almost a decade, more than half the depreciation time of the cars. With first principles sales techniques it's possible X could sell these moon chips now and deliver them made on earth 6 or 7 Moore's law cycles later by a different company, like with the solar roof or hydraulic brick machine from alibaba, way cheaper.