Frome here:

Proliferation of once-secret human augmentation techniques. Surreptitious recovery of Spartan tissue and organs, industrial espionage, independent research, and the release of some augmentation protocols for medical usage has substantially eroded the UNSC’s monopoly on super-soldiers. Though the knowledge and tools are now available for any sufficiently motivated (and wealthy) private party to replicate a Spartan-equivalent enhancement package, few see the need to match the recruiting standards and scope of enhancement afforded to UNSC Spartans – and are willing to settle for cheaper and more invasive augmentations with unknown medical drawbacks and psychological costs. Many of the gene therapies, artificial organ implants,