My productivity is down this year a lot. And I mean a lot. This is not because of WFH but do to the situation we live in. I think I wrote like 50 lines of code this month. I just can't stand it anymore, being locked inside the house with a computer on. I was WFH pre-pandemic but travelled, surfed, played social sports, went to cafes, beach. I was productive but my life was balanced and nice. Lets not even talk about the home schooling period where I had to be a teacher and full time worker (like many parents).
Now? I hate my life. I just wake up with the desire for it to be night and go to bed and have the day behind me.
I actually think during this pandemic I would be more productive in an office, due to having some kind of normal, getting out of the house, see other people and talk with others. My gf just started a new job this week that required her to go to the office. You can't imagine how much I envy her right now. I wouldn't mind a 50 minute commute or whatnot, just for a sense of going back to normal.
So yeah, I think you are doing a very unscientific 'study' based on the current situation the world if going through.