I think this is key:

"On top of that, there is currently no reliable way to accurately measure how AI use among businesses and consumers contributes to economic growth."

No doubt people are using it work ( https://www.gallup.com/workplace/701195/frequent-workplace-c... ) the question is how much productivity results and to whom does it accrue.

Partially this is AI capability (both today and in the past), partially this is people taking time to change their tools.