Big caveat to the productivity claim is that it’s concentrated in lesser experienced engineers and vanishes or goes negative with highly experienced engineers. This intuitively makes sense and generally agrees with my experience. LLMs move your baseline towards the mean. If you are below average it improves and if you are above it hinders. But also in my experience, my memory retention of the work done with an LLM is…
Where are you getting that from? It's a productivity tool. Someone who knows what they're doing can leverage LLMs to improve their productivity. Someone who doesn't know what they're doing will be able to increase their output but not do it as effectively and with lower quality.
If anything, it now requires more skill to maximize. If you have strong product and engineering experience you can get even more out of an LLM than one of those skills alone.