Newer translations are substantially better, I've been told, but I think it does have to do with politics. That said, the politics element merely emerges as a thought experiment from a question of how we create our subjectivities (our psyche) and structure our desires to live the most desirable life. The metaphor of the way that a republic should be constituted is introduced as a way to explain how we should constitute ourselves. So it's definitely at the least first about how we constitute ourselves as individuals, and delving into the idea of how that relates to potential constitutions of city-states.

But in much of Plato's work, most key claims made get directly undermined within the same dialogue, the others in others. What we regularly see in simplistic first/second year takes, like the focuses on arguments made; reducing dialogue between mutiple characters with specific personalities to point-form sets of claims and conclusions, or the assuming that the character of Socrates is a mouthpiece for Plato's views, totally undermines what for me is what's really good about Plato - the literary and dramatic techniques that at every point undermine my confidence in my own 'knowledge', that brings me to seek out better and better answers to questions while accepting that there is no arriving at any answers, because that journey provides the conditions for the most desirable way to live. From straight up lies, myths, complex forms of irony that have you oscillating between multiple interpretations in constant flux such that you never arrive at an answer but always seek, to imagery that breaks from the orthodox to undermine itself and what came before.
For me what Plato actually believed is largely irrelevant, his work sets out always to destroy our confidence that we know and to get us to seek better information, by building subject-making directly into his work, and I think that's super interesting and unparalleled in any of the philosophy I've read (which is a very limited amount).

There's more cool stuff written about Meno than Republic to make these things clear, but once you're familiar with it you see it everywhere in his work. I had a decent-sized Plato phase many years ago, without which I wouldn't have eventually become an anarchist.