a 20% boost is huge, for 3 years since chatgpt. even if it stopped there, that's 20% fewer people that need to be in your role, which is at least tens of thousands of jobs
10-20% productivity posts have been happening regularly over the course of my career. They are normally either squandered by inefficient processes or we start building more complex systems.
When Rails was released, for certain types of projects, you could move 3 or 4x faster almost overnight.