It should be obvious by now that the Frankfurt School (and all other dialectical philosophies) are substantively wrong about a key element of that approach: history is not moving toward some preordained end. Progress is not slowly revealing some sort of truth about human nature, the idea that there is ultimately one, and only one, correct way for humanity to live has no support. Isaiah Berlin (yes, another European Jew, but of a later generation) wrote extensively and persuasively about this: that there are a plurality of value systems that could make human beings happy, unfortunately they are not all compatible with each other, hence the necessity of choosing. The difficulty humanity has in choosing which of many equally plausible set of values is where war and conflict come from, would that we could find a better way. But the ultimate evil (says Berlin) is Absolutism--the insistence by one faction that their solution is the one and only Truth, and therefore they feel justified in imposing that "truth" on the rest of us, by force if necessary.
If history has no inherent direction, then phrases like "civilized" and "primitive" cannot adhere to their traditional meaning. So-called "primitive" people are, on an individual basis, just as cognitively complex and well adapted to their environment as we the more "civilized" ones are. Similar considerations apply to other subjective terms of value judgement when applied to entire categories of people.
The ideal society might then be defined as that within which everyone is maximally adapted to their environment. The problem is that we are all in competition with each other, trying to secure access to and control over social resources at each others' expense, so any one state of affairs is inherently dynamic and subject to change. There is no ideal society to strive toward--merely an arena in which the competitive advantage of large scale cooperation ensures that living conditions slowly and incrementally improve for most (though not all) people.
Procedurally, the purpose of social criticism, as practiced today, isn't to propose solutions to anything. It's to point out the way in which the distribution of power protects the status quo and hides itself behind cultural stories. Movies, music, clothing, narrative, aren't inherently *bad* per se, but they do conceal and protect the status quo, including unjust inequalities.