rationalfrummie,
I agree that they can exist, but they aren’t the bulk of what is occurring. What is occurring is flirting(in halachic terms: conversation where pleasure is derived because the other person is of the opposite gender), and that is ossur even if it never leads to anything beyond.
If we want boys and girls to be able to handle shidduchim, college or work, then have them interact at family shabbos meals with polite conversation in front of their parents. But frankly I think those concerns are overblown.