In which country are 16 year olds not allowed to work?

In my nation 16-year olds may work outside of school hours (school is mandatory until they are 18 years old). There are other hard limits on which types of jobs and the time of day they may work. Work shall never interfere with school.

Which suggests that the child labor laws for 16-year-olds are there to keep 16-year-olds in school, rather than school being there as a place to put 16-year-olds who are banned from employment.

In Germany you can leave school at 16 and work full-time.

That is not true for most states in Germany.

After 10 years of mandatory school most states have what is called "Berufsschulpflicht" until you are at least 18 years old.

That means you have to learn a job, which is not the same as working full-time and still considered education.

16 year olds in Germany are employed and they can work 40 hours a week.

Claiming that 16 year olds "can not work because they have mandatory school" is false.