Emma, your implied answer is absolutely correct.
Businesses and other organizations did not fall apart when anyone was gone. I don't know about many other people, but for me and most of my co-workers, we were not expected to call in or maintain any kind of connection to our places if employment. The ability to do that was nearly impossible anyway.
The closest to doing that I remember from the 60's and 70's was an attorney friend who constantly contacted his answer service when he went anywhere, even in town. Sounds sort of like folks who constantly check their cell phones these days.
I had the good fortune to work for the U.S. Army in the early 80's, stationed in the Nürnberg Military Community. Of course, as a U.S. government employee I received almost the same benefits as if I was working in the States. But I learned a lot about the way things worked in Germany from the many German workers we had on our military facilities there.
You might be interested in the details of how annual and sick leave are earned and used by U.S. Federal Employees. This is the primary source for that. I'm including the links because they illustrate what I think are our weaknesses on these very important quality of life issues and may give some hints on the leading example for why we get so little vacation time.
Ordinary workers like I was, earn annual leave at a rate of 4 hours per 2 week pay period or 13 days per year for the first 3 years. After 3 years, the rate is 6 hours per pay period or 20 days per year. After 15 years it is 8 hours per pay period or 26 days per year. That's the max.
You can carry over 30 days to the next leave year if you're working in the States and 45 days if you're working overseas. This is called the leave ceiling. It is use or lose. Any accrued annual leave in excess of the ceiling is lost if not used by the final day of the leave year. You can receive pay for accrued annual leave up to the ceiling when you no longer work for the Federal Government.
Sick leave rules are similar but not exactly the same and a lot more detailed.
It is accrued at 4 hours per pay period no matter the length of service. There are no limits on how much you can accrue, but you lose it all when you leave Federal employment. It can be used for a variety of reasons beyond your own illness, but there are some limitations.
Sick Leave Usage Limits per Leave Year
No limitation for an employee's own personal medical needs.
Up to 13 days (104 hours) of sick leave for general family care and bereavement. Be sure to click on this link at the website for definitions of what is included here. Especially compared to what I learned in Scandinavia last year, this is particularly weak.
Up to 12 weeks (480 hours) of sick leave to care for a family member with a serious health condition.
I very carefully used up all my annual leave before I left the Feds, but I had over 300 hours of unused sick leave left over after 3 1/2 years there.