How much human labor is needed to run a semiconductor fab? This isn't exactly a new shipyard being announced. It seems like the perfect investment for an aging society, and might pay dividends in helping to support the automation of other industries.
Japan also already supplies a lot of critical materials for semiconductor fabrication, and has a lot of experience in the sector. They also have a well-developed domestic mechatronics supply chain. It seems like a fairly straightforward thing.
It takes a fair amount of people. You have techs that keep the floor level stuff running, process engineers, maintenance techs and engineers, facilities, IT & automation people, logistics, quality assurance, management, admins. I bet you're talking more than a thousand people for a big facility.