TV shows tend to be formulaic, so the direction is a lot less critical. It is similar episode to episode, it is why a lot of actors get director credits for shows they act in; it is seen as a way to get OJT in directing so they might have a career off camera after the show wraps.
TV shows will typically have a set of veteran directors the showrunners can call on to do the day in and day out work and bring in guest directors if it is a special episode or arc. For character development ‘bottle’ episodes, you can use less experienced directors because the actors and camera crews and everyone basically know what to do. It is a matter of getting an excellent script to make it memorable.
For lower episode count streaming series, the ‘prestige’ TV as it were, they tend to have fewer directors. *Andor* had three directors for a 12 episode arc. Since a series like that is similar to one long movie, the direction is more important because it isn’t formulaic, and you need more than one because having one director for a 12 episode release would add a bunch of development time to the series that is essentially unnecessary.
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