I can't fathom how crazy it gets to model once you try to consider compilers, architectures, timings, temperatures, bit-flips & ECCs, cache misses, pseudo and "truly" random devices, threads, other processes, system load, I/O errors, networking.

To me it seems mandatory to work with some abstraction underneath that allows factoring a lot of different cases into a smaller set of possibilities that needs to be analysed.

It's also how we manage to think in a world where tiny little details do give you a likely insignificantly different world-state to think about.