“You can’t deeply review what you no longer deeply understand.”
The productivity gains from AI coding tools are real. The cost is that you stop being able to evaluate what you’re shipping. A 2026 study cited here found AI-assisted developers scored 17% lower on understanding and debugging. That’s not a rounding error. The seniority pipeline is the buried problem: juniors skip the struggle that builds judgment, seniors delegate until their depth evaporates, and nobody notices until something breaks badly enough to matter.