Episodes that once opened with a montage of earlier events now frequently begin cold. The change follows the way series are released rather than any shift in how stories are told.
The recap solved a gap in time
Weekly broadcast placed seven days between episodes, and a season could stretch across most of a year with interruptions for holidays and sport.
Viewers returning after that interval needed reminding which threads were active, and the recap supplied it in under a minute.
Where a season is released at once, the previous episode may have finished moments earlier, and the same segment becomes an obstacle rather than a service.
Recaps also revealed what mattered
A recap necessarily selects, and the selection tells a viewer which earlier detail will become relevant in the episode about to play.
That is useful for comprehension and destructive for surprise, since an unremarkable moment appearing in the montage announces its own importance.
Writers working for an audience watching in sequence prefer to place that information inside the drama, where it does not carry the same signal.
Skip controls changed the calculation
Interfaces now offer to jump past both recaps and opening titles, and a large share of viewers use those controls automatically.
A segment most people skip is expensive to produce for little return, and it consumes running time that could serve the episode itself.
Services measure this precisely, which is why the decision to include a recap is now made with data rather than by convention.
Weekly release brought some of it back
Services releasing episodes on a weekly schedule reintroduced the same gap that recaps were written to bridge in the first place.
Those series often carry a recap again, though shorter and more selective than the broadcast version, since the interval is a week rather than a season.
The feature therefore tracks the release pattern closely, and its presence is a reliable indication of how a show expects to be watched.
Exposition moved into the writing
Without a recap, necessary information must be reintroduced within scenes, through dialogue that reminds without stopping the action.
Done poorly this produces characters explaining things to each other that both already know, which is among the most common complaints about modern serials.
Done well it is invisible, and the craft of doing it well has become a more central part of the television writer's job than it used to be.