I think you are seeing a very unrepresentative group.
I work from home full time.
Today I worked from 6.30am until 9am - with a little break to sort son out for school, and get myself dressed and house sorted.
Then got my nails done (Hen Do tomorrow!) from 9am - 10.30am
Worked from 10.40 - midday. Ran from 12.10 to 1pm
I shall work till 5pm (with short 10 min breaks here and there), shower, make dinner and sort house/son. He's got Scouts from 7.45 - 9.15 so I'll work then as well.
That's about 9 hrs work today - with a fair bit of not working during core office hours. This is unusual (I rarely get my nails done).
In my little breaks I catch up with WhatsApp or FB or MN, pop a load of washing on, hang it out, chop veggies for dinner, open the post - amazing what you can do in 10 mins.
I have a brain-intensive computer-based job and have an app that locks the computer down every 55 mins to make sure I have a break.