Not actually that surprising when you consider the nature of the privatized military industrial complex. Cheap and efficient weapons isn't where the profit lies. You have low margins, you need to build a lot of factories and warehouses to store them, hire lots of workers, and so on. Making fancy toys like F-35s in artisanal batches is where it's at. You design something that's really expensive to build and that requires a ton of maintenance, and then you milk tax dollars off of it.