>The entire premise of a system is that it removes the need for careful attention.

I think this premise is flawed or, at best, too narrow. A system is just a logical grouping of items that perform a function. Sometimes that function can be to reduce cognitive burden, but it doesn't have to be. A "vision system" like what humans use does not reduce attention, but increases/enables it, while a autonomic nervous system can reduce attention. The ability to increase/reduce attention is not the central principle of a system.