Game of Thrones suffered from overtaking the novels. It was less about being dragged out (in my opinion) and more about not having George RR Martin at the helm with a thousand pages material already written and waiting adaption.

Martin is famously slow at writing the books, but that lead to some really deep and complex storylines. However when you try to compress that process into < 1 year and with different writers at the helm as well, then you’re inevitably going to end up with something that feels rushed and stripped of any substance.