We just spend way less time with them -- but Carter and Scott are meant to be very close friends. But Scott hides this even from him.
I, of course, really care about Scott and Kip. But it is a pretty straightforward story compared to Ilya and Shane. They have a lot more complexity. they're also much younger and there's so much more for them to navigate.
I just read the 5th book in the series, though, and THAT is the character I felt desperate to see find someone. Rachel Reid does a really good job of showing how isolating the closet is.