The most frustrating takeaway from the original SRI PSOS architecture is that we had the blueprint for true hardware-level Zero-Trust in 1979, and we abandoned it for deployment convenience. By anchoring security in unalterable, hardware-tagged capabilities rather than software-defined access control lists, PSOS eliminated privilege escalation at the physical layer. The SRI Hierarchical Development Methodology (HDM) didn't just 'test' for security; it mathematically proved structural isolation across distinct abstraction levels. Modern monoliths have spent the last thirty years trying to bolt software firewalls onto fundamentally porous kernels, when we should have been building on the hardware-enforced capability model PSOS handed us