You work to live not the other way.
Family is more important than a job. So yeah, giving only 20-30% of your life to your job and keeping the rest for your family makes more sense than the other way around.
Above 6-7 yo they are obligated to go to school, unless you homeschool, which is also incompatible with fulltime, good faith employment.
There is no point in a child's life that requires 100% attention during the day.
Even once they reach preschool/primary they don't.
You are of the opinion that it is more important that an employee be available 100% of the time from 9 to 5, I am of the opinion that it is most important that an employee get their job done.
I would 100% prefer a competent employee where I have to block out some brief segment during the day, than someone less capable where I can schedule a meeting whenever I like from 9 to 5.
I would also 100% prefer an employee I can trust to do their job regardless of supervision than someone who needs hand holding for everything.
Handholding is for interns and new employees learning how to work in industry (vs. academia or opensource).
I expect FTEs to be able to do their job without persistent oversight, and I expect them to do their jobs without persistent oversight.
The same goes for middle managers though.