Agreed, there's a difference between "nobody has the time or money to care" and "no human mind has the capacity to hold the whole model at one time." I was for

Agreed, there's a difference between "nobody has the time or money to care" and "no human mind has the capacity to hold the whole model at one time." I was fortunate to get a computer and electrical engineering education that ran the gamut from making basic organic semiconductor structures in the lab and up the pyramid through logic gates, adders, a custom processor on an FPGA, writing a custom RTOS, patching the Linux kernel, and writing a userspace application. There are no black boxes anywhere on that stack - someone somewhere knows or knew how it worked - but the last time that some systems engineer could claim comprehensive understanding of the stack was probably no later than the early 80s. Individually, one can build broad competence, comprehension, and a career at some height in the pyramid, and can have limited comprehension of things directly above and below your zone, but the whole pyramid is superhuman.