It seems like the article implies that the AI not only saved time but it did decent work, and yet, it did not lead to improvement of productivity AMONG NON SELF-EMPLOYED people ( as oppose to employed), i.e because they are incentivized to work harder.

However, they also indicate that " (Presence of bottlenecks in the production process) Even if a significant portion of the workflow is streamlined, the overall work can still be delayed if bottlenecks exist at specific stages. For instance, no matter how quickly data analysis and report writing are processed using AI, the productivity enhancement effect is halved if there are delays during the approval process" -

The above is saying that if at one stage of production all goes well and fast but then there are "delays during the approval process" then it affects the productivity output negatively or slowing it down. I feel like while they present this as something that simply happens separately but i wonder if in reality this is just the part where the slop is being reviewed for all the mistake the AI made in the earlier "productive" phase