Yes, this was my concern with applying the lessons more broadly. I would love to see a similar assessment for a company that was substantially staffed from other locations to see how much this is a universal picture or not.
I can't mention the company, but I was told from someone at a very large financial company in the US that their productivity tanked over the last year. I won't be surprised if this is generally the case for WFH.
So you heard from a second-hand source that productivity at a bank tanked, and that's making you think that negative WFH productivity is the norm? Maybe base your opinions off a little more information than a friend's story.