Reasons :
1) Every student has a specific diet they might be allergic to some kinds of food which means they could accidentally eat it because they’re not fully sure of what’s in their food, which may lead to a serious health problem.
2) Everyone should have the right to take their provisions from home for example almost every boarding student forgets a personal belonging or just isn’t able to carry it around because it’s not allowed, it could be a life changing or an important memory for the person or they just don’t have anywhere else to put their stuff.
3) Sometimes the food doesn’t get to someone’s taste which means someone could be used to eating the same amount meals for the past 7 years but when they change diets it could get them sick because they’re trying foods they’re not so familiar with.
4) Low quality foods, I’ve heard that a lot of boarding schools don’t use good quality foods which may harm the student If they eat it on daily basis.
5) When students move out, especially studying aboard they’d want to feel welcomed or at home at least. So having some of their provisions from home would be a great idea to make them more comfortable.
Hope this helped :)