> It’s even harder to train new people in Old technology
My thought is, that new people are trained on modern technology (how to acquire and set up a secure laptop OS or how to configure a smartphone), and older employees still "run" on the old technology.
It’s even harder to train new people in Old technology. Just write a code base in Fortran And see how hard it is to find a developer.
I’m quite confident you could send messages all day using the methods of Ancient Rome without being ever detected.