Are we looking at the same graph? What I see is that there was a huge spike at the onset of COVID, and then it flatlined and even corrected a bit, and in the end seems to have resumed the same trajectory it had before COVID.

If I understand correctly, the spike in 2020 was not any kind of jump in real productivity, either, it is an artifact of how the calculation is made -- there was a sudden drop in hours from low paid workers who typically have a lower than average contribution to productivity (as measured), so laying a bunch of them off skews the per-hour calculation. Then as things settled down companies re-hired, and then over-hired.