I'll give you my take on one particular aspect of this term - 24 hour news cable channels - but I don't think it's widespread.
TLDR: the emergence of high polarization results from the need to use editorializing and punditry to fill time. This is what I consider to be the defining impact of the 24 hours news cycle.
How 24 hour news started
When I was finishing up college in the US CNN (founded in 1980) was coming of age. It was the first 24 hour news broadcaster and it was glorious. If you were a news junkie you could watch it at any time and catch up with was going on in the whole world.
They were operating on a 30 minute cycle. Every 30 minutes it would loop back to whatever was going on. If new news came in, it was slotted in. If not, most of the cycle's content would repeat. So while it was addictive, it wasn't very sticky - you watched your 30 minutes then you'd be done for most of the day. There was no reason to watch 2 cycles back to back. A plane crash might occupy 5-10 minutes of that 30 because the rest of the news also needed covering. A 24 hour news channel that would mostly only be watched 1x30minutes or 2x30minutes, each day, even by devoted viewers was a pretty (self-)limited proposition.
Back then there was big question of whether it would be lucrative to run 24 hrs news channels. CNN also had a lot of on-location reporters adding to costs (reporters who could be affiliates, but still wanted $$$). And... they were mostly reporting facts, not giving their opinions. You could think of them as the Reuters of TV reporting, brief, to the point, mostly neutral.
There were no Anderson Coopers or Sean Hannitys back then. Anchors existed, but weren't national celebrities like a Walter Cronkite.
How to improve profits?
Obviously CNN's gamble paid off, you could run a 24hr news channel. But, how to improve profitability?
Their challenge, and the modification of the 24 news cycle, as I see it, isn't the fast pacing. News has always been fast paced. News also has a long history of sensationalism:
The term was coined in the mid-1890s to characterize the sensational journalism in the circulation war between Joseph Pulitzer's New York World and William Randolph Hearst's New York Journal. The battle peaked from 1895 to about 1898, and historical usage often refers specifically to this period. Both papers were accused by critics of sensationalizing the news in order to drive up circulation, although the newspapers did serious reporting as well.
Their challenge is to produce 24 hours worth of varying, sticky content at reasonable cost. And even harder to do so on subjects that people find interesting. I.e. no coverage of sheep shearing in Outer Mongolia for fillers. American audiences aren't going to develop fascination with global news, all of sudden, except when it impacts the US directly. Or is noteworthy enough, which is self-limiting.
Fast forward to now.
CNN has a lot less on-location teams than they used to. Or rather, the proportion of their air-time that is delivered by exclusive, on-location, teams is much lower.
CNN "news the sh*t out of"* any news. Plane crash? That's going to be 3-4 days of saturation coverage.
Most of all, CNN saves money by not so much focussing on reporting itself as endless streams of pundits interpreting the news. That plane crash? You're going to get hours of aeronautics university professors, bereaved family members, union representatives, authors about airplane safety, all talking their little heads off to Anderson Cooper, in studio. Quite cheap (the professors and authors all get exposure from it). Since 2020? By Zoom to boot, less logistics to get the experts in.
The brilliant bit? It's very sticky and coverage can be extended for hours.
The problem
Granted, in the case of the 737 Max mess, extensive coverage of how Boeing captured FAA regulation to the point where the company got to decide what was safe enough might be warranted, even if most of the facts took a while to emerge. Arguably, a more "normal" plane crash would not need as much coverage. But rest assured CNN would put it on very high rotation anyway.
However, when that same extensive coverage has to stretch out to cover minor political events, day-in, day-out, it can also degenerate - as it has - to a lot of editorializing and pundits telling the established viewership the angles they like to hear, rather than just laying out the facts.
It is hard, inherently, to provide a lot of interpretation, or even "in depth coverage", while remaining fully neutral. Read Reuters - which more than most, cultivates neutrality - online and you will be struck by how short many of their articles are.
Am I down on CNN? Yes! I consider them lightweight, very partisan and with a low signal-to-noise ratio (lots of time used to cover not much).
But they have an equally dysfunctional counterpart in Fox News, founded in 1996, which also has hours of political commentary masquerading as news, from studio. Same reasons. At least as lightweight, partisan and time-wasting (to me).
I dislike one marginally less than the other, but it doesn't matter which one. In both cases neutrality is taking a back seat. Most likely, if you love CNN you hate Fox and if you love Fox you hate CNN.
Both work best when a good amount of partisanship is mixed in to enhance stickiness. They are essentially news talk shows for most of the 24 hours cycle.
This not-really-reporting aspect has even, successfully, been used in defense of news anchors by their own network:
XXX News again moved to dismiss. The motion argues that when read in context, Mr. YYY's statements “cannot reasonably be interpreted as facts” and that the Amended Complaint fails to allege actual malice.
At least under this format, rather than CNN's original short rotation cycles, polarization is the inherent consequence of the need to fill airtime over 24 hours. Cynical manipulations to increase audience stickiness by presenting more biased, sensationalistic, "entertaining" news can certainly make things worse, but is not in itself required.
* adapting a popular profanity from The Martian
