> If you calculate GDP per worker, and call that productivity, then productivity is declining.

"Productivity" is output (generally economic) per operation. For workers, it's typically economic value (to the employer) of an hour's or day's labor. For machinery it's typically economic value of operating it for a period.

GDP per worker doesn't make sense and is not what anybody uses.

BTW, WFH can increase productivity from the worker's PoV since they no longer have to divide their salary (the economic value of their work) by the commute time, just the time when they are working. So same numerator, smaller denominator.