Note that self-reporting productivity gains is a completely unreliable and unscientific metric. One study[1], small in scope but a noteworthy data point, found that over the course of the study that LLMs reduced productivity by ~20% but even after the fact the participants felt that on average their productivity had increased by ~20%. This study is surely not the end-all be-all and you could find ways to criticise it or say it doesn't apply or they were doing it wrong or whatever reason you think the developers should have had increased productivity, but the point is that people cannot accurately judge their own productivity by vibes alone.

[1] https://metr.org/blog/2025-07-10-early-2025-ai-experienced-o...