A lot of software in 01972 was also effectively tied to a literal single installation. Most of the software people ran under Unix at the time was only present on one of the ten Unix installations and has consequently been lost. The shrink-wrapped mass-distribution software epoch was still ten years in the future.

That's why software archaeology from that era is hard, but it's still a lot easier than today's cloud software. It's a lot more complex, much more of a moving target, and is more interdependent with other services all of which would have to be either emulated or restored.

My other point was that we've gone back to the mainframe era. The PC revolution has mostly been abandoned.