The characters developed. It just wasn't HUGE developments. But as bps just said, when HAS there been huge developments?
E moved on from his efforts to run a solo business and joined an existing company, finally stabilizing his career independent of Vince. He also got engaged to Sloane and for once chose her over the group. Seemingly a real character development that should lead to him being more about Sloane than the guys, but who knows? It doesn't feel like a lot because he's always been the workhorse and the boyfriend, but it kind of is.
Drama actually had a real change in personality those last few episodes. He found some peace and basically grew up. They really hammered home hard this episode with how impressed the casting folk were and how everyone thought he was unlike he ever was. Presumably Drama's past the pathetic need for stardom and is finally content being who he is. And oddly enough it may have opened the door to making him a star, probably because it was his self destructive obsession that constantly did him in.
Turtle started school, had a serious relationship, and ended it. Its pretty simplistic but Turtle's always been the least mature of the bunch so he basically just went through his first love and heartbreak.
Really, Vince and Ari are the only ones who didn't really mature and you can argue Ari did by forgiving Lloyd. But the "entourage" really did develop probably more than they ever have before. But they're still best friends and the people they've always been. That's not gonna change.
