https://dc-office.org/basedata#p5 I highly recommend reading the Okinawa prefectural government's DC office fact sheet. Short story: There'd be a lot more useful economic activity from developing the land these bases are on.

(Okinawa has DC offices because the prefecture and the Japanese mainland gov't are not aligned on these topics at all. The prefecture basically wants these bases gone, and don't really want SDF bases there either. Tokyo wants the bases.)