alt Hacker NewsIdeally. But that requires the correct abstraction, requires keeping it up to date.... that's basically an unachievable ideal. You either have overabstraction/overengineering (most codebases) or you have repetition. Repetition is actually more preferable in the LLM-world because you have to keep less stuff in your head. And the LLM's head too.
Even if something does look copypasted, it might actually be semantically distinct enough that if you couple them, you'll create a brittle mess.
Additionally, there's always going to be global changes (update the code style, document things, refactor into a new pattern, add new functionality to callers, etc.). The question isn't whether you use your lanuage's tools or you do it by hand, the question is whether you use an LLM or do it by hand :P
Totally fair, but 42 if-statements across 32 files isn't something you need to fix with like ... a grand refactor or hexagonal architecture or event sourcing or whatever the overengineering pattern du jour is. You can fix that with a utility function or three, and a file/class/module/whatever that owns the code relating to some of those conditions.
I'm not some DRY zealot, but I've been in the "this system needs really similar changes to a ton of geographically distant code for simple changes" salt mines a lot. The people who say that kind of spaghetti is unavoidable are just as wrong as the ones who say it can only be fixed with a grand rearchitecture by a rockstar.