Their spouses who may have worked outside the home, were home.
If they had not worked from home previously, chances are - they didn't have a dedicated office space - or even equipment.
Add to that the constant low-level stress of being in a pandemic with constant media impressions, massive social change events/activities (at least for those in North America with BLM and the moronic exit of the Orange-moron), and it isn't a stretch to think that productivity has been down somewhat.
Never did WFH until the pandemic, and will probably continue working from home for some time after things open back up. I have a hard time seeing how my day-to-day will differ significantly post-pandemic.
But a true work from home setup likely involves having a dedicated home office space, with the right setup. Even now, a lot of people don't have that.
I would assume for people with children being able to offload them to public education institutions during work hours will be significant difference.
From my experience (2 days/week WFH before pandemic):
1. People with kids have to babysit (I do not have children, but people who have are noticeably impacted by this)
2. Everything is closed, so casual outing to coffee shop or just grabbing a lunch with colleagues not possible. Some goes for just going to gym for a bit.
3. Before the pandemic, sometimes we did morning in the office filled with debate/design work, then lunch and then go home to bunker down and code. Again, not possible now.
4. Two adults in one room makes meetings annoying (well, basically openspace but without the free food).
5. Team beer is remote now, which I mean, kinda works. I get drunk anyway. But still, suck a bit.