I've worked from home, successfully, for many years, and I disagree with that criteria. Everyone works from home differently, and I know people who can rock their work exactly because of the added flexibility to care for their home and family on their work breaks. It decreases the stress in their life to slice their day in different ways, and allows people with busy lives to do better on all fronts.
There are many different ways to manage remote teams - some are hands-off, only concerned about whether the work is done. Some monitor their people to be sure they are 100% online during "working hours". Many are in a middle ground, with expectations set of specific response times to Slack, IMs, emails, etc. Likewise, there are many different remote working styles. Some people do well with a typical 8 hour day. I tended to target a 40 hour week, but that would be made of many 2-3 hour chunks throughout the week, not 8 hour blocks.
At the end of the day, you have to trust your team to do their work. The companies that are resistant to their remote people handling personal tasks during their "working day" don't truly have that trust.