Only a small proportion of the program involves software, and at that they were, for example, designing VR/AR helmets as a feature. What people are talking about being an entire industry was tacked on as a minor feature.
Imagine designing hardware where your single product is developed as computer tech advanced from 1993 to 2006 (program inception to first production flight, more or less)
There was an estimate that the program employed a quarter of a million people, because of how spread out contracts like this are it's hard to really come up with a comparison.
JSF is on a similar level of complexity of the entirety of Google, and has been in development about five years longer.
Which back then was seriously on the ropes, with SJ coming back to turn it around. Nobody would have listed Apple as an industry leading company. How times change.
Sure, people "depend" on FB for comms etc blah blah, but the world functioned fine before them if not maybe slightly less convenient. Netflix, come on. It's just entertainment. Nothing more. Google? Maybe search could be built to work again. Amazon? Maybe people actually buy local again. Apple? So we don't have luxury devices that cost more than some people make in a year.
*Obviously excluding the sudden loss of jobs. It's just a thought exercise.
Even just a single component, like the engine, is a massive engineering undertaking. If the company developing the powerplant under-delivers the entire program can be a bust.