Is photography apprentice the hardest job, and it is also a job where you can't learn anything?

No, everything is learned from the basics. He who suffers hardships is a master.

Photographic assistants in the studio usually just pose, light, reflector, spread skirts and so on. There is not much difference between the cast and crew, such as pushing the rail car, or having the opportunity to help with focus, collecting equipment after filming and so on.

It's hard, but this industry has basically come out like this. The most important thing is to ask more questions.