I am biased towards fantasy adventure, so my review comes with that caveat. I think the directors have done well adapting the characters to the story, but it lacks depth. We sort of see this fantasy world, but they didn't take time to develop it. We get pieces of it through the episodes and plenty of action/fantasy/adventure along with it. It feels like there are missing details. As others noted, story is a bit condensed and its clear they are trying to get to the point. There's enough here for fantasy lovers to digest, but you also have to sit through cringe "romance" scenes.
Your 5 star reviews are coming from book lovers, which I understand. However, this is not a 5 star television series.