Well it was based of the wars of the roses everyone being a murderous psychopath is not pulled from nowhere.

I do have to agree though game of thrones did what a lot of American tv does and just coasted of a good early series. The boys is worse it only had a good pilot and has been coasting since with episodes that only imply something is going to happen later without anything ever happening. This is why tv should be mapped out in how many seasons it will be to begin with