Anybody who watches a lot of films has noticed that they are longer. The average has drifted upward over decades and the drift has accelerated among the biggest releases.
The reasons are more interesting than the usual explanation, which is that directors have become self-indulgent.
The exhibition constraint disappeared
The largest structural change and the one people rarely mention.
When a cinema had one or two screens, runtime directly determined how many showings could be sold in a day. A film thirty minutes longer cost the exhibitor a screening, and that arithmetic exerted real downward pressure.
Multiplexes with a dozen screens weakened that constraint considerably, since a long film can occupy one screen while shorter titles rotate faster elsewhere.
Streaming removed it entirely. There is no showing to lose, no schedule to fit, and no cost to an extra twenty minutes.
Which means one of the main historical forces keeping films tight simply stopped operating.
The prestige association
A perception effect that is real and slightly embarrassing.
Length has become associated with seriousness. Awards contenders skew long, and a substantial runtime signals ambition in a way that a tight ninety minutes does not.
Whether that association is deserved is doubtful. It exists, and it means a director arguing for a longer cut has an implicit argument about importance on their side.
The same effect runs in reverse. Comedies remain short, because the genre carries no prestige expectation and because comic timing degrades over length.
Franchise obligations
The mechanism that has done most to the biggest films.
A film that is part of a larger series has work to do beyond its own story. Setting up future instalments, servicing characters from previous ones, resolving threads inherited from elsewhere.
None of that is dramatically necessary to the film in front of you and all of it consumes runtime.
The result is films with a complete story of conventional length plus twenty or thirty minutes of connective tissue serving a schedule.
Director leverage
A genuine change in who decides.
Final cut authority has historically been rare and is now held by more directors, particularly those with a commercial record.
Studios also compete for prestige filmmakers, and creative control is a currency in that competition that costs nothing upfront.
Which means fewer films pass through the process of somebody with commercial authority insisting on cuts, and that process, for all its reputation for philistinism, produced a lot of tighter films.
What length actually costs
Beyond the audience's patience.
Attendance drops. Very long films see measurably lower repeat viewing and are harder for families and older audiences to attend.
Intermissions have returned in some markets for the longest releases, which is a practical acknowledgement of a physical limit.
And there is an argument, hard to prove and widely believed within the industry, that length correlates with weaker second-week performance because word of mouth includes the runtime.
What has genuinely got better
To be fair, since the trend is not only bad.
Some stories are better served by length, and the increased willingness to make three-hour films has produced work that would previously have been compressed into something worse.
Streaming has allowed films that would not fit any theatrical model to exist at all.
And the loosening has particularly benefited films from traditions where longer runtimes are normal and which were previously cut for international release, frequently badly.
The version I would defend
Length is a decision rather than a virtue or a fault, and the question is whether the material justifies it.
The films that use their runtime well generally have a reason for it — a structure that needs the space, a pace that is the point, material that would be damaged by compression.
The ones that do not are usually long for the structural reasons above rather than for anything on screen, and the tell is that you could describe what to cut.
When an audience leaving a film can readily identify twenty minutes that contributed nothing, that is a fairly reliable verdict, and it happens considerably more often than it used to.
The data behind the impression
Worth checking rather than trusting the feeling, and the feeling is broadly correct.
Analyses of average runtimes across large samples of releases show a steady upward drift over several decades, with the effect concentrated among the highest-grossing titles rather than spread evenly.
Mid-budget films have changed much less. Comedies have barely moved. The increase is almost entirely in blockbusters and in awards contenders, which are the two categories with the structural pressures described above.
Which means the general claim that films are longer is really a claim about two specific categories, and the ordinary film of conventional length is still being made in quantity — it simply receives less attention.
The home viewing effect
A factor that cuts both ways and is worth adding.
A three hour film at home can be paused, split across evenings, or watched in the background, which removes the physical constraint that made length costly in a cinema.
That has arguably encouraged longer work by removing a real limit.
It has also changed how such films are actually consumed, since a substantial share of the audience for a long film at home is not watching it in one sitting, which affects pacing decisions in ways that are still being worked out.