It likely depends on the country, but I am sure there is no lack of pampered/spoiled children at boarding schools. In the US, where free boarding schools are practically unheard up, it is even more likely.

The adults should be ensuring you don't grievously injure or harm yourself, and that you're returned in same/better condition.

You can always ring up your parents and ask for stuff, it's not like you are adopted by the school and lose all contact with your parents, nor are you earning a wage at 13 going to boarding school.

Lots of kids going to public school and/or with rough home lives learn "sink or swim" just as well or better than someone going to boarding school. I just found it odd to say you're learning to "sink or swim" when you have so many safety nets there to catch you if you did sink/fall.