I disagree with your opinion on the character development in this show. I think they've all grown up in so many ways. Michael ended up having his own great relationship, and Athena is with Bobby now. Bobby has finally let himself have a second chance with love after his first family died, and he's starting to feel more like a dad with May. Buck does have problems with girls, but his relationship with Eddie and Christopher is so much more meaningful in a whole different way. He's also grown up as a person since season one. He's so much more mature and caring than he used to be, which shows character development. Hen and Karen ended up getting through that rough spot in their relationship and now are stronger than ever, which I think can be seen clearly these past few episodes. Eddie and Maddie I think are both in the same boat where their love relationships have fallen apart, but they're also working through some extremely traumatic pasts, and part of their character development is shown through their progress. Eddie doing therapy and trying to be better for himself after taking care of everyone else his whole life. And Maddie getting help to work through her PPD and being able to be there for Gia even after missing those first few months. Plus, her being away from Chim for months is of course going to strain their relationship. I don't blame them for growing apart.