Do kids not want mentors?

I was a mentor for a few teen girls and they all wanted to stop after about 6 months. What we’d do is just hangout and talk and eat lunch. I talk to other mentors and they told me their teens have ask them to cut back and not visit or talk to them as much too. Do kids want mentors/a friend or am I wasting my time? It only worked out with one teen I had where we actually still talk to this day and have a great relationship. All the others just kinda fell off. Why?