The 70% AI productivity myth: why most companies aren't seeing the gains

Summary

"I've never felt this much behind as a programmer."That's Andrej Karpathy, OpenAI co-founder and one of the most respected AI researchers alive, writing in December 2025. He describes a "magnitude 9 earthquake" rocking the profession. A "powerful alien tool" handed around with no manual.Now consider the narrative you've been hearing from vendors, executives, and LinkedIn thought leaders: AI has collapsed software development costs by 70-90%. Development velocity is through the roof. If you're not seeing these gains, you're doing it wrong.These two realities don't fit together. If even Karpathy feels behind, what hope does the average enterprise engineering team have?The answer is uncomfortable: the 70-90% productivity claim is true for about 10% of the industry. For the other 90%, it's a marketing hallucination masquerading as data.Let's start with what vendors promise.GitHub claims Copilot makes developers 55% faster. Google reports similar figures. Microsoft suggests 20-30% improvements. OpenAI's enterprise report touts that users save 40-60 minutes per day.Now let's look at independent research.A randomized controlled study by METR (Model Evaluation & Threat Research) found something that should terrify every CTO: experienced developers using AI tools took 19% longer to complete tasks than those working without them.Not beginners. Not interns fumbling with ChatGPT. Experienced engineers. On codebases they knew. With tools designed to make them faster.They got slower.The Stack Overflow 2025 Developer Survey adds nuance. While 52% of developers report some positive productivity impact from AI tools, only a minority experience transformative gains. 46% now actively distrust AI output accuracy, up from 31% last year. The number-one frustration, cited by 66% of developers: AI solutions that are "almost right, but not quite", leading to time-consuming debugging.Perhaps most telling is the perception gap.In the METR study, developers predicted AI would make them 24% fas...