Ultimately one of Martin's clearest points of view is that every single lord in GoT is flawed, in a way that should really block them from leadership. He clearly hates the concept of a monarchy, and with Dany, the point is that she's entirely unfit to rule even a city (as Barristan, a book character entirely destroyed in the show, tries to point out to her constantly).
Because the show isn't supposed to be about the individuals in the first place.
It's about society, what it does to people, how it frames how we view ourselves and those around us, and what the norms and violation of those norms does to individual actors writ large.
Except in the last two seasons whene it's about "all your friends and their adventures".
Dany is important because she is in her words rebelling against the society that cast out her family but through her actions is implicitly not doing anything to dismantle society for the better. She just centralizes it around her like you said, it's a crafted metaphor for "nation building" and the lies that come with it, US imperialism, the heft of power and what those in power in a society that's been conquered will do to remain in power while keeping the powerless under heel through the conquerors.
She's never, at any point, painted as a savior by
society, but by
herself. Aside from the "white savior" scene we're shown and told repeatedly that she doesn't actually do anything meaningful to dismantle the society in which they live and replace it with a better one. She just takes on element of it and recodifies it.
It's why we never get a POV chapter of smallfolk with her as the focus. Because it's explicit through her alliances and crafting in Meereen that she is perceived as just "another thing to deal with".
And that's it, yes, slavery is bad, she's doing the right thing abolishing it, but that's all she does.
There's no "and then" and broad structural generational changes, society foundationally
remains the same.
Which is why society rejects her, she, a foreign power, has come in and told them that their way of life is wrong and that she, the enlightened foreigner, will change everything and make it better. While also keeping literally the entire power structure of society as was before in power because that's to her benefit towards her "real" goal of conquering Westeros and claiming her birthright.
Society cannot change to build her superstructure, she has her views of what a society
is and refuses to delegate that to what society
actually is and how she can best manage it. Martin is very clear that all of these people
should not be rulers because they are bad at it and the way that society has evolved means that monarchs are far more harmful than good as we progress through what is a society on the verge of collapse.
She doesn't need to be perfect to be a genuine "breaker" of the wheel of power. To unmake and rebuild in an egalitarian image where there is still ostensible power structures but things are better, the structures more amenable to the society in which they reside. But she doesn't do that, everything is simply what
she believes to be right.
She doesn't free the Unsullied despite knowing that using them is wrong because it's in her self interest to do so. Which under the society she functions within is a normal and rational choice in that position, but it goes against her perception and internal coda. They are, functionally, her personal slave army.
She doesn't dismantle the nobles of Meereen and impose a
new structure, a
new cycle, because she doesn't
understand their society and is thus completely unable to solidify her power which drives her anger and resentment, which is why she stays. She can't just plop someone on the throne and leave because it's a direct assent against HER power, against her individual mandate as Empress.
Society doesn't change unless you do as is stated repeatedly in the books, "Rip it up, root and stem".
It's why the North refuses to bend the knee to the Bolton's, it's why the people in Kings Landing don't really care which pompous dink sits on the throne until Young Griff comes along and promises them better material conditions.
Society is the primary actor, the motivator, the characters agency goes in so far as society allows them, which is fine, that makes them human, their flaws and issues.
But Dany was never an explicit liberator and freer of the oppressed because it is not in her interests to consolidate her power, from her position in society, to do so.
But she does some token things because her morality and sense of self thinks that it's what a proper society should do without realizing the ramifications of it. Meereen teaches her that such changes don't matter if you don't change society around it, but in the show and probably in the books, what she takes from it is a personal insult to her, that they are not rejecting society, they are rejecting her benevolence.
Which would have worked in the show if they had done that over 3-4 seasons instead of 20 minutes. Foreshadowing is not character development, I 100000% agree with that statement, but that's why the natural development towards this makes sense and is something to build, but is unworkable when presented as a "twist" for the sake of cheap drama.
I get it, killing slavers isn't a bad thing (rightfully so) in modern context, which is why we're shown it in the books, because Martin uses modern sensibilities to make things feel more natural to the reader and because it's a fantasy story so you don't need to be "historically accurate". But the slavers were also the benchmark of their society, the underpinning, and she killed a lot in a rampant display of power to demonstrate her ferocity and martial ability, but she didn't "pull them up root and stem" after that display, which left her with a society just like it was before, just as stratified as it was before, and just as unequal as it was before.
That's my opinion on it and what her character represents in the narrative, anyway. She's flawed, trying to do the good thing while satisfying herself, it makes her human, it makes her a compelling character, it's why she's so interesting. But I don't think we need to ascribe her values and morality that she clearly doesn't represent because no monarchs in the series represent the "ideals" to which they profess such great importance. It's why Sansa's conversations with the Hound about the nature of the "true Knight" are Martin all but telling the audience that these are pretty ideals, but that they are incompatible with the form of power that manifests from the pursuit of them. We "root" for her because her ambitions and desires are the clearest and many interpret them to be the most rooted in altruism and a more egalitarian sensibility. Her flaws and desire for power doesn't remove that.
