I bet, you won't see much part-time work in many fields and professions.
My colleague had a baby. He would like to spend more time with the baby. He asked to reduce his hours. The boss said yes because its the law and we no longer live in the middle ages.
Lots of people I know do 4 days a week - there isn’t much social pressure to work 5.
Which kind of implies a social pressure.
Would you claim that it is the same outside of line of work?
From what I understand, people who enjoy a large degree of freedom already, they can get those things relatively easy. Parental leave, working from home, part-time, all part of the privilege that comes with the job.
But that is a limited subset of society.
Middle-management or upper-management in IT? Outside of IT?
At least from what I hear from Germany, not working _overtime_ for middle- or upper-management, as a medical doctor at a university hospital, many research positions is considered "lack of commitment". Almost irregardless of what you deliver. Probably you won't get fired, but you have to be exceptionally good so it doesn't reflect badly on you.