I think part of what you're reaching for is the concept of anti-fragility: https://en.wikipedia.org/wiki/Antifragility

Properly speaking, that would be a characteristic of the entire production process, including the people, rather than a property of the code itself. (At least for now. Stay tuned with AI for further updates.) Still, you'll see it in the code.

Yeah that seems about right! I mean, it is a property of the code itself also, but the code is not the only place quality resides. I think it's fair expect that any piece of software will require updates, and a high quality code base is easier to modify than a poor quality one. But, as you point out, surrounding process, people working on it etc etc etc are also super important.

Software very rarely exist in a vacuum