People who slack at work by hide it by having lots of meetings / playing politics are useless whilst working-from home because they don't know how operate when their productivity is more visible.
When we all went on lockdown recently, I noticed that at first people were careful to create a "proper" workspace that was not only silent but also photogenic for their camera. Naturally, a kid sees a closed door with the most interesting new thing in the house happening on the other side. The only proper recourse is to bang on the door.
Even within just a few weeks, things have relaxed considerably. Now, I rarely attend a meeting, even when there are higher-ups in attendance, where there are not kid noises in the background, folks going on "mute" to deal with a meltdown, even just letting the kids play in the same room. Going shopping during the work day, when the stores are less crowded, is completely normal now.
When all of this started, some folks said: "Finally this will normalize working from home." Maybe it will go even further, and normalize folks having a real life.
I absolutely love this. I love seeing my colleagues contextualized in their private spaces, that reflects their personal choices, humanity, wholeness. In the office this is reduced to a 2x5' desk.
Office as a space also has a sense of self-importance to it. It is not unlike a church or a stadium where the purpose of the gathering is super-salient and the participants' rich humanity is backgrounded. Working from home, it is harder to be reduced to one's function as a worker, it is impossible to forget that you are a human with a life when constantly surrounded by the cues that remind you of that life, in the space that you live that life.
Sorry, ahem, bathroom.
My closest collaborator falls pretty squarely under "terrible at written communication", but we still have sufficiently frequent face-to-face time to be about as productive as before.
I'm in agreement with the general sentiment elsewhere in this thread, though. I've found nothing about people's WFH productivity that's surprising. People with kids are handicapped, but are often determined enough to find a way to make it work. For everybody else, it seems like the inequality in productivity just goes up, and it's harder to mask non-productivity by socializing well.