I don't disagree with the article but it may give some readers the impression that pre-AI hand-written code wasn't fragile.

Here's the famous commentary about Oracle RDBMS codebase of 25 million lines: https://news.ycombinator.com/item?id=18442941

Every big company codebase with millions of lines devolves into a similar state. The small codebase starts with clean conceptual integrity. It then inevitably decays into incomprehensible spaghetti code as more people are added to it. Various reasons for it including the later devs caring less about the code than the initial team of devs, deadlines, avoiding refactoring because of fear about breaking things, etc