Pretty sure the "great productivity while WFH" is contingent on having a dedicated workspace (I mean, I guess it can be shared with other work-from-homers in the household, but it should be dedicated). Which isn't something everyone can afford. That's why, even as I advocate for WFH as the default, I think companies should still have offices where people can do their work if they need to.
My last job was 100% WFH and I tell people this all the time who ask how I do it.
"Dedicate a work area for work and nothing else".
All I have on my work desk (which is an actual desk in a smallish room I converted for the purpose) is a monitor, keyboard and mouse and a coffee mug full of pens. The only thing in the room that isn't work is a Dualshock 4 PS4 controller that I use for gaming when I'm on lunch breaks or after work is done and I feel like playing some street fighter.
You don't just work at the house and expect to be productive. Much like muscles in the body working out for a marathon, you have to train at it, exercise and make deliberate efforts to get better. You don't just show up and run if you expect to have a good time.
YMMV though. I'm lucky to be a single-ish guy with a cat and no kids.
Yes, if I ever go back to WFH I'll make sure to have a dedicated office. You need a room where "work happens" and nothing else. The human mind needs boundaries.
