The stories did not devolve. The arc followed the natural path from enslaved sapient beings. It was well thought out. It is a shame that more people didn't want more of an intelligent story that organically follows the characters and actions at the start of the series. The direction of the story should have surprised no one. HBO, like so many streamers and stations are not willing to give shows time to develop grow and follow a path that viewers may not enjoy initially. So many successful series 40-50 years ago that are still praised now, would not have made it more than one or two seasons in today's world. With the amount of new content available, viewership needs to be evaluated over a longer period if time.