Btw Sasuke uses ren’ai when talking about love, which means romantic love. This word cannot be used of mean anything platonic.
Then we have kakashi say you don’t need a reason to love in response to Sasuke talking about romantic love. Then goes on to explain how Sakura doesn’t have a reason she loves him. This isn’t out of a selfish desire to own him.
Literal translation: “she doesn’t want to make you her thing.”
Kakashi is highlighting that her wanting to save him isn’t out of a selfish want to possess him. Everything she does is for him and his well being alone.
Basiaclly, Kakashi’s response to Sasuke’s understanding of romantic love is that you don’t need reasons, for example, sakura here loves you without reasons, without wanting to benefit for her own sake.