As with any such question of the evolution of style, there are multiple elements that influence the emergence of particular patterns. I like to take a cross-disciplinary approach to see which elements of style experience medium-specific, versus genre-specific change. My background is film music composition, musicology, and theater, so I’ll mix observations from these.

In the evolution of style in cinema, you have to consider the constraints of the medium, as well as its advantages. You also need to consider what an audience’s expectations would have been, versus how a filmmaker may wish to play off of these expectations.

First, technology. It became practical to film images and record sound simultaneously when a method was developed to imprint sound directly onto a film reel using a series of dots which could be fed into an optical reader, which could then play them back as sound. Unlike the grooves in a phonograph record or a magnetic tape, this method lacked a fair amount of fidelity and had a low bitrate (volume differences were hard to capture). The advantage was that because it was hard to control the speed at which a film was recorded and played back (making each performance of a film slightly different), these sound cues were always the same, and always matched the images.

Now, because particularly at that time, the equipment needed to film a sound enabled reel was expensive, and the film was expensive, it became somewhat common for stage actors to be hired, and for scenes to be carefully blocked and rehearsed many times so as to reduce the number of takes required. This also reduced the amount of film needed to be expended for a production. Film development and editing was a very significant element of the cost of a production. And because sound was typically recorded using a single live microphone above the actors heads, projection and clarity were important skills.

And here we come to changes in tastes. Directors, knowing that whole scenes would be shot in single takes, were thus free to write “snappy” dialogue that provided a large amount of exposition and conflict in words, rather than visually or atmospherically, as later film directors would find possible. This drew heavily on theater and radio drama, both of which predate the talking picture, and both of which took full advantage of the fact that recorded sound is intimate and can be made to feel immersive and real. Realism became achievable - at least in the sense of physical space as the sound of an actor’s voice. Multi camera setups meant that more content could be recorded simultaneously and cut together easily, allowing for tv sitcoms like I Love Lucy.

This drove the genres of noir and suspense to the forefront in filmmaking, whereas burlesque and large scale drama had been the focus of much of early filmmaking. But with audiences becoming accustomed to the medium, film was applied to more than just capturing amazing images and exotic locations. It could now capture performances, and performances meant quick dialogue and drama. It meant the medium could also provide much more exposition than ever before, and films could be made more cheaply, because large scale productions no longer were needed to provide a sense of excitement. People would come to hear the actors, not just see the pictures. Much of what Alfred Hitchcock did in film is based on this synthesis of stage and radio. The ability to create realistic scenes, and to heighten drama with tight pacing and dialogue allowed writers to push the genre into psychological exploration. Over time, the “staginess” of earlier talkies became more subdued, as camera technology allowed movement and visual focus to again bring audiences something new and fresh.

It would take the advent of Betamax video recording and linear editing, ironically, for many of these tropes to return to popular cinema and film, with writers like Arron Sorkin again drawing on childhood experiences of long takes and snappy dialogue, bringing theatricality back into tv and movies where it had been shunned in favor of ever growing realism.

(Edit: by the way, elements of this style of dialogue writing were coming back into mainstream film by the 1990s, not only from TV writers like Sorkin, but also filmmakers and writers like Quentin Tarantino. His script for the film Crimson Tide, which he doctored but wasn’t credited for, is a masterclass in that form of overlapping dialogue that filmmakers had been hesitant to employ because of its seeming anachronism.)

For a near perfect idea of where these two eras of film overlap, the film The Great Dictator, by Charlie Chaplin is an ur-example. Being a product of silent film, but also an accomplished stage actor and director, Chaplin showed for the first time that spectacle and quiet drama and subtle emotion could be melded into a single film. That film in many ways was the last old style picture, and the first new one.

In the past I have provided other long explanations of style shifts for things like voice pitch and speed, which I’ll try to find and link to. I mean the above as merely a brief summation of how technology both enables and limits creative style in ways that filmmakers and later tv showrunners respond to in different ways. Style is a product of both opportunity and limitation. Following the development of technology and performance technique can help us to see how style is a natural product of what is achievable at any given time, as well as what is at any time considered new and exciting.

Edit: HEY! I got into the digest this week.

It occurred to me as I was reviewing my answer that one of the things I didn’t focus on was the end of the noir era in film and why it happened.

There are as always many reasons, but one of the biggest was once again, technology. The ability to do longer takes with much more detail and better lenses, to use cranes, dollies and set up remote shooting locations really brought back a new era of spectacle cinema. 70mm stereoscopic lenses would turn their eyes on major westerns, war epics, musicals, and historical films. New sound technologies made vocal performance much more subtle and precise, meaning people with soft, almost effeminate voices like Marlon Brando and Martin Sheen replaced the Bogart generation. Film became at once more realistic, and also more hyper-real, with the ability to show much more dynamic range, cut together many more shots, and to film grand scenes from multiple spots at once.

So the need for tightly paced dialogue driven films, while it didn’t go away, shifted more to TV, where classically trained actors like William Shatner carried this stage vocal tradition from Shakespeare productions forward into TV movies, and eventually into series television with Star Trek. In fact the voice of Captain Kirk may be the final voice of that particular era of film, radio and television. Shatner, one of the most prolific actors in television history (and at the time possibly the single most prolific tv film actor alive), set a precedent for a certain kind of TV that became a cornerstone of American and British popular culture for decades.

In fact his performances were an important early influence on a very young Quentin Tarantino (who would ultimately resurrect the shatneresque, theatrical style in some of his films).

And he does it. With. That voice.