The basic purpose of a phone is to communicate between two people. I want to convey some information to another phone. I can talk to him over phone or I can send as SMS. For these activities a normal mobile is sufficient and no smartphone is required. A student never required a smartphone but some students may require an ordinary mobile phone. I think a student who is in high school, may not require any phone. But if he is staying away from the house and he has to communicate with his parents then a normal mobile phone. Once the student enters the UG course then the parents may consider a mobile phone. A smartphone can be purchased for PG student.
But these days because of online classes to all the student's many students are opting smart phones. Even primary school students are also using smartphones. Now it has become a necessity for students.
Wheteher parents like it or not, they are forced to give a smartphone to their children for their studies.