You do realize that all that is also expensive, and limited? We haven’t invented room temperature superconductors yet, and battery technology is far from perfect. There is only so much lithium and cobalt in the entire world. Yes we can now use things like sodium, but that’s a technology that’s still young and needs more research before it’s full potential is realized. There is also a reason we have overground cables and not underground. Digging up all that earth is hella expensive.