The all-at-once release was presented as the format streaming had made possible. A substantial part of the industry has since moved back to weekly episodes, for reasons that have little to do with storytelling.
A binge compresses the conversation
When a season arrives at once, the audience consumes it at different speeds, and discussion becomes impossible to hold without spoiling something for someone.
The result is an intense few days of attention followed by silence, which is a short window for a production that took years.
Weekly episodes synchronise the audience, so everyone has seen the same amount and can discuss it, which sustains attention across months.
Subscriptions follow the release pattern
A viewer who joins to watch one series and finishes it in a weekend has no reason to remain subscribed.
Spreading the same season across two months requires the subscription to be maintained across two billing periods rather than one.
Platforms measure this directly, and the difference is large enough to determine release strategy independently of what audiences say they prefer.
Marketing needs time to work
A campaign for a series released at once has to do all its work beforehand, since afterwards there is nothing left to promote.
A weekly release lets a campaign build on the reaction to earlier episodes, which is cheaper and more credible than advertising alone.
Awards campaigns benefit similarly, because a series in the conversation for months is more visible to voters than one that peaked in a weekend.
The writing is not the same
Episodes written to be watched consecutively can carry a scene that only pays off two hours later, and can dispense with recapping.
Episodes released weekly need to re-establish the situation, end at a point that sustains a week of waiting, and give each instalment its own shape.
These are genuinely different structures, and a season written for one pattern and released in the other tends to feel wrong without the viewer identifying why.
Hybrids exist because both arguments are true
Releasing several episodes at launch and the remainder weekly gives the audience enough to become committed while preserving the extended run.
Splitting a season into two parts months apart serves the same purpose across a longer period.
Comedies are the common exception, since a half-hour episode has less to sustain a week of anticipation and the form has always rewarded consecutive viewing.