Understanding this is one thing; the question is what can be done about it. I see at least three reasons to hope for future progress. The first is that a lot of productivity growth comes not from existing firms, who tend to be incremental about it, but from new firms.
A new firm with a new product or service tends to see giant leaps in productivity as it goes from being a start-up to the “hockey stick” growth phase. A firm only makes that transition once, but an economy can reap the benefit over and over if there is a strong trend in new firm creation.