I don't think anyone claimed that Greece and Rome were great states of freedom, because until the rise of America, "great states of freedom" weren't really a thing at all.
That's a large part of Romanticism in a nutshell. Yearning for the good old days (which were terrible). As the Romantics happened after the United States were established, your point is irrelevant.
Actually, the Dark Ages were acknowledged as such even back to the Renaissance. If we're using the term Romantics strictly as in Romantic Literature, that style tended to favor themes that
weren't civilized, or that took a sterner view of civilization. For example, Walter Scott wrote about the scottish highlands and popularized the wistful theme of Twilight of the Celts, in which the old untamed highlands were falling to modernity; there was also Nathaniel Hawthorne and his books like Scarlet Letter, in which civilization was less pure than nature. In Romantic literature, you're much more likely to get an ode to noble savagery than an paean to the civilized Roman. Viewing the Roman period as superior to the Migration Era was by no means a creation of the actual Romantic Period. In fact, the Romantic period is perhaps the first volley in the war to question the fruits of civilization.
You're judging the past on an arbitrary and elusive modern standard for freedom.
It is not a matter of judgement. I am not passing moral edict against the political freedoms of the Roman Empire, I am explaining to you all why the Dark Age is not a thing.
It is judgment. All of this categorizing and describing of eras is merely arbitrary opinion with no firm measure. It must necessarily involve judgment somewhere, and if it isn't
your judgment, then it is the judgment of someone that you listened to, but whose arguments you didn't internalize, so it falsely crystalized into "fact" in your mind.
But that is not the point. Slavery is not moral no matter how you treat the slaves. Owning other people is wrong, because everybody should have the right to seek their path in life, not live as the tool of another without choice. Even if you don't stay a slave, nobody should ever be a slave for any period of time.
That's a common conceit in modern people, but then you really are simply saying that everything before the 1960s was a Dark Age in your view, and you refuse stubbornly to acknowledge that certain ages have been a darker age than other dark ages. That's an obtuse way of making a grandiose demonstration of your morality. Makes you feel warm inside, but accomplishes little else.
Cut to the chase. You have to be in a time period where there are long bouts of peace, good roads, trade, construction projects everywhere, libraries, grammar schools, laws that recognize all freedmen equally and limit abuse on slaves.
Or you can choose to live in a time period where lordlings squabble and fight petty wars like those described in the
De Excidio of Gildas, where knowlegde of how to build anything bigger than a meadhall is lost and Roman ruins are literally thought to be the "work of giants" from myth, where literacy rates plummet, where there's a separate law for different classes, based not on fluid notions of master and slave, but a fixed ethnic definition in which Gallo-Romans have no upward prospects and can never be better than a Frank.
Here is your choice. Perhaps both are dark in your grandstanding morality, but one is
considerably less dark. Which one?
also why I hold the political views of a filthy progressive, as to remove what control remains and place the powerstructures of our society firmly within the hands of the general public and cap their avenues of oppression.)
The general public, huh? So, who is he? I never heard of a person called the General Public. What you'll get when you entrust so much power in a man named General Public is rather a Generalissimo instead.
The folly of progressives lies therein. You actually think the "general public" exists as a sentient entity capable of self-determination, when all power actually must devolve ultimately to individuals. Individuals with real last names, names like Stalin and Mao. Best, then, to make power diffuse rather than centralizing it, eh?