It varies wildly by genre, director, writers, etc. Basically any generally about "modern films" as a whole is bound to be inaccurate, but this one especially so.

Because it's completely unheard of that film, music, art, games and so on often have certain traits depending on which era they are from? I would almost place a bet on that's what OP means, and the point is probably that he has noticed that constant dialogue is a prevalent trait in many movies in this era compared to other eras.

But I completely disagree with the premise. It sounds more like emotional "back in my day!" arguments rather than anything backed by data.

Someone already mentioned A Quiet Place, a movie from 2018 with only 90 lines of spoken dialogue. Another one with sparse (but not that sparse, of course) dialogue I watched this year was 1917.

Sure, most movies in general would not have the kind of structure and dialogue as 2001, but I'd say they definitely shouldn't.

I read somewhere that in the early early days of talkies (back when the vitaphone orchestra was a thing)...if there was no source for music to come from (eg, a radio, phonograph, singer, concert in the park, etc), there was no music. They figured the audience wanted a source for the music, not just a constant film score.

Of course the silents had a constant score, often piano, often orchestra.

Some old movies are near constant jabbering, but rarely is it breaking the fourth wall to talk at the audience. (Example: His Girl Friday, 1940.)
The convos were also more than just useless interjections. [This category of "useless interjections" includes swearing, um's, uh's, "like," etc. There was a movie where I felt that if you removed all the useless time-wasting filler talk (which was done in that movie because they didn't know what else to say?) the dialogue would have been about 1/3 less, leaving room for silence or dialogue between people which might even, idk, perhaps even advance the plot line.... Unless maybe the plot was so thin they were trying to stretch the dialogue out to fill their allotted time.]

The book actually has a narrator tl;dr the plot and theme of the rest of the book at the end of the caveman section (so, about 30 pages into it). >_>

Yeah, but the book was written by Arthur C. Clarke BEFORE the movie was made. Yes, it was in collaboration with Kubrick, but based on early drafts, not the complete movie.

Here's a quote from Kubrick:

There are a number of differences between the book and the movie. The novel, for example, attempts to explain things much more explicitly than the film does, which is inevitable in a verbal medium. The novel came about after we did a 130-page prose treatment of the film at the very outset. ... Arthur took all the existing material, plus an impression of some of the rushes, and wrote the novel. As a result, there's a difference between the novel and the film ... I think that the divergences between the two works are interesting.

Trying to make sense of the movie for oneself can be interesting, admittedly - though I just watched it for what it was & never bothered to try to "explain it" - but it's when someone tries to pass off a personal interpretation as "how it really is or should be" that it becomes wankery.

Why do older films have longer takes with richer dialogue compared to modern films?

I agree with the points of films having too much exposition. But another thing is, tastes simply have changed, shifted and wobbled over time into new forms.

Back in the whenever, when you filmed a man crossing the desert, you did so in terrible detail.

Nowadays, you'll probably just fade cut to their next situation.

CinemaSins will help you laugh at a lot of movie making tropes. I love their channel.

And what about the ending? Did you understand everything what was happening and why?

only one i know is under teh skin, which is modern an' was... interestin' (my friends keep makin' me watch weirdo movies i dont understand, lol)

i honest lee dont buy teh opening premise of op, nor teh complete lee unknown an' unprovable notion of wut would happen to that 2001 movie 'nowadays'

Btw many modern movies have less talk like bladerunner.

I think "domination of the author" is a different reason than "shutting down imagination".

Take for example Blade Runner (original movie). Ridley Scott considered Deckard a replicant - that was his vison. But some people (including Harrison Ford himself) thought differently - considering Deckard to be a human. All because there was no "exposition" in that regard.

I think today a lot of directors (or scriptwriters for that matter) want establish their genius (at least in their view) ideas clearly, so that's why they put in the film narration and other stuff, so everyone would get, what they want to say. In other words they indeed try to "dominate". No one of them thinks about viewer's imagination.

It's not an issue of too much or too little talking. It's a matter of respecting the audience's intelligence and modern film writing is generally pitched at a level so that young children can comprehend it even if the subject isn't directed at them.