I've looked at jobs at places like this (some requiring quite high clearance) and the pay is hilariously bad, and I don't make anywhere near peak FAANG rates (or work in FAANG)
50% pay cut for a DevOps/SRE role requiring a Q clearance (DoE version of Top Secret I think)
You can't find employees because the job isn't exciting (you're probably not NASA) and the pay is bad. Maybe your recruiters are bad too.