I’m not sure which show you’re referring to, but when you begin to look at shows or movies through that lens, you start to see how each component hinges on the others. You can have great lines delivered poorly, vs. quality actors who just can’t save the crappy lines, or a crappy storyline, etc.
And the director is the head coach, but depending on the project and the people involved, sometimes a director’s presence is bigger and it more heavily influences the writing and acting and camera work… and other times there’s less influence, and more freedom is given to those other contributors.
Series are different because the show’s creator or showrunner is really the broader “director,” but each episode can have its own individual director among several other directors for other episodes. So some episodes can have a different creative or visual feel within a series, and that can be by design.