In the youth drama, everyone is a minor, and their thoughts are still immature. Most importantly, after graduating from high school, they will go to their respective schools and go their separate ways. If you are not in the same school, there will be fewer opportunities for contact and the relationship will gradually fade.
Qian Sanyi thinks more. Considering that he and Lin are not in the same place and can't take good care of her, they may not confess. Of course not together in the end. This is also a common routine of youth drama.