QED: people literally in the notes of this post right now dragging LotR, award-winning litfic, Stephen King, and disagreeing about whether or not the breakfast example (or for that matter the Starbucks example†) count as "showing character".
Heck the one that made me laugh most was the person with tags going "ugh this is how people get coffee shop AU brain" and like on the one hand I deeply sympathise with exasperation at the proliferation of this AU - I don't like it either!
But I hate to be the bearer of bad news: it is extremely popular which means for a huge number of people, that pacing works perfectly for what they want out of that writing. You may regret that and wish that there was a higher amount of a different kind of story, but that doesn't mean shit about the "objective" value of that style of writing, because there is no objective value.
A lot of people clearly enjoy Stephen King's pacing at least enough to, you know, make him Stephen King.
"Fluff" is extra detail and writing that you personally don't enjoy and don't think adds to the story.
Now the flipside of this is that like . . . people who think Stephen King has shit pacing aren't wrong either. They aren't wrong about what they enjoy, and about what writing works for them. Which means that if this is your audience, you need to have more compact and loaded pacing than he does in order to appeal to them.
Preferences will have cultural, generational and contextual tendencies. I've always found it fascinating that the same people I know are for instance much more forgiving of a slower, more spread-out pacing in their fanfic reading than in their professional reading; in their LitFic reading than in their romance reading; I know someone who is flawlessly bilingual and has totally different tastes in their reading from one language to another (specifically: absolutely impatient in English, first to DNF a book if it "lags" to them even SLIGHTLY . . . suuuuper patient in Mandarin, loves lush, extended, slowed down everything in Mandarin) and so on.
Expectation and convention are both relevant here. That's why it's so hard, and what you want out of things makes so much difference: if you want to appeal to the widest possible audience in a particular language, genre, time, etc, you're going to be trying to match a certain set of expectations.
I have tended to find a more useful question is less "does this scene/whatever advance these various things enough to count as load bearing" or whatever and more "is this scene achieving what I want."
YBEB-and-extended-universe is very slow paced. It's slow paced on purpose. It's that way because what I wanted to do was something that needed space, that needed less "one load-bearing wall" and more a whole web of thin threads from so many directions, all taking a piece of the load, because what I was doing with it was exploring the spaces of trauma and recovery that felt real enough for me that I could be happy with where I ended it, and the idea that things could continue from there, that the whole thing wasn't doomed to veer off a cliff the first time a stressor hit - basically the opposite of how the ending of Frozen made me feel.††
And y'all I promise, some people hated it. People on AO3 either forget or don't care that the author can see what you put in the notes and tags of your bookmarks and I have a solid number of what amount to "note to self: I hate this one, don't forget and try to read it again" although I will forever be critical of the one person who complained that all they did was sit around and have feelings and eat sandwiches because there is exactly one sandwich in the core fic, and actually what they do far too much of is drink coffee.
Am I totally happy with the pacing in YBEB? no of course not, I wrote it ten years ago. Almost literally ten years ago, in a week it will be ten years ago to the DAY that I started it, and also, I'm a writer, I'm never actually totally happy with what I've produced. But I'm not going to lie: some of what I'm not happy with is that it's actually too thin in places; it did what I needed it to internally but is a bit threadbare in terms of a standalone argument.
But I'm also aware that if I were trying to sell a story with its structure and pacing as a standalone genre novel in a professional context, it probably wouldn't get anywhere, because its structure and pacing aren't right for that set of expectations and so on.
Because context and audience are everything, and nothing is objective.
The most useful question for me has always been "is this piece of writing doing what I want it to do, and if not, why". That does mean I have to know what the fuck I am wanting this piece of writing to do, which is always a bit tricky, and is also the part that gets elided/assumed/taken for granted in most of these conversations (generally by the person giving the advice assuming that what people want or should want is "to write something I would enjoy and approve of and think is structurally sound and compelling/to write something the way I would write it" and taking that as a given), and is sometimes the hardest thing to figure out: "is this scene doing what it needs to" is impossible to answer for sure if you don't know what you need this scene to do, and "advance plot, theme, world, character, etc, or even do two of them at once at all times" isn't actually helpful unless you know what advancing (or whatever) looks like for what you want on this project.
Unless you know what you WANT out of this. And thus if you're not SURE, write the damn thing anyway, you can always fix it in post.
(for the record: I do not save my darlings. No matter how much I loved the idea of a scene or whatever, if when I look at it I come to the conclusion that it doesn't belong, and it isn't just a case of moving it to later but it truly just doesn't belong, I delete it, because if I don't its existence will distract me. But I do generally have a solid idea of what I want out of something, even if it's a thing nobody else wants from me, so.)
†I will admit I am bemused at how disinterested the OP seems to be about how someone in this day and age comes to think Starbucks orders are worthy of that much description and engagement. Presumably there's more context to that which makes it "obvious" that this was a pointless conversation, and that's fair, but from what's reported here, ngl: "this character thinks it's worth describing a Starbucks and Starbucks order in 15 minutes of detail" counts, a priori, as something that demonstrates character to me.
††Frozen and its subtext is very important for a lot of people; for me, especially at the time it came out, what I was struggling with most was a chronic depressive state in which the most exhausting external thing was other people's concern and other people's worry - nice problem to have, right? And in some senses, yes: I was incredibly lucky.
In other senses how bad I felt and how unwell I was kept being literally exacerbated by the fact that all these people I loved were unhappy that I was unhappy - not that they deliberately burdened me with that, but that I'd even know, and that also none of their love and support and caring and everything else . . . made me feel any better. I was in fact at a point of struggling with my chronic illness wherein I was coming to terms with the fact that none of the things I thought would fix me . . . actually would. That the problem would not be solved by academic success or by popularity or by whatever, because my brain was sick and didn't know how to enjoy any of those things anymore and until we found a way to get my brain to remember how to experiencing positive things, I could not actually access a happier state.
So for me the end of Frozen made/makes me wince: not because I don't relate, but because I do, because I experienced that one sudden lift and relief and then the mental illness came back and it's so much worse when you think you have! conquered everything! with the power of love and connection! and then . . . . you haven't.
And then your very relapse feels to the other person like a rejection of their love and support. And shit gets ugly. And for obvious reasons my emotions-brain had zero faith that when that happened, anyone in that story would be able to deal.
So the point of YBEB was for me to weave a story and context that meant that I could believe that when That Kind Of Shit Happened, the people involved would be able to meet that Fucking Mess and figure out how to get thru it.
