Medical industry, code that gets shipped has to be documented, even if it's not used. It doesn't mean we can't ship unused code, it just means it's generally a pretty bad idea to do it. Maybe the feature's requirement might change during implementation, or you wanted to do a minor version release but that dead code is for a feature that needs to go into a major version (because of regulations).
> I can’t think of any regulations in any country (and I know of a lot of them) that dictate how you do code changes
https://blog.johner-institute.com/regulatory-affairs/design-...
That document doesn’t say that, as far as I can tell. If you’re using a compiled language, the dead code likely gets removed anyway, it is never shipped.