The difference is twofold. First, junior devs who ask for code reviews on massive, 2000+ line diffs get coached, and eventually fired if they persist at it. And second, even the most prolific junior engineer would take years to write what Claude is capable of generating in an afternoon.

When Sundar Pichai announces that 75% of all new code at Google is AI-generated, their stock price goes up. If he were to announce that 75% of all new code at Google is now written by junior engineers, this would trigger a massive sell-off and a lot of employees would resign.