What is the point of Naming and Necessity and modality?

Disclaimer: I'm a layman when it comes to philosophy. I know of the big names, and then I mainly specialized in philosophy of science. The highest quality anchors I have into the whole philosophy of language discussion are Carnap and Rorty. So I may not have the full context of discussion w.r.t. philosophy of language here.

I always hear of the Hesperus – Phosphorus meme but I still don't really get it. Like, I don't get what kind of arguments it buys you and what kind of way of thinking it shifts you towards.

Like, even though I'm not well versed in the whole practice turn w.r.t. language and inferentialism and all of that, for that, I can vibe out roughly what people are saying. Rather than trying to say that the definition of a chair is because I need to a priori map it to these four legged things and get "definitions", flip it on its head and think about the meaning of words through use and shared practices (and then Sellars extends this to "the space of reasons" and ties it back to Kant's discursive judgements, and later on Brandom through inferential relations).

At least from a philosophy of science angle, from my eyes, this ties in heavily w/ how philsci people stopped trying to ask for a justification for science or a scientific method and instead started focusing on scientific practices (Nancy Cartwright, Ian Hacking, Hasok Chang are really good here).

From my perspective then, Carnap is an important target here (either strawman or not) because he, despite his relative neutrality with retreats back to pragmatism and such, still approaches the problem from a fundamentally "wrong" angle. (and it's not even like he's "dead" either; see Friedman, so my mental model is probably too shallow here, but point is, I have a model for him in my brain atm).

But I genuinely have no clue what Naming and Necessity, and modality buys you. What cool things can you do with it? What perspective changes does it bring? I don't even have a base anchor point to then build on top of.

Sometimes I genuinely think that ruminating on Plato and Aristotle is more philosophically fruitful than any time I try to meaningfully engage with the whole modal revolution & analytic metaphysics, I just genuinely don't get it. Like, what are we doing here?

I've been reccomended some modern literature in "the domain" of this, e.g. Schaffer's Grounding papers, but even after reading through some of them I don't get why anybody would really… care? Is this just a problem with me not really caring about metaphysics?

And it's frustrating because some of the people I respect definitely were trained in this era (1950s-2000s), and all analytic philosophers are trained in this area (well, at least all the ones I've talked to, might be school bias though), so there's something I'm missing out on here. I've probably been reading, say, philosophy of science, wrong, since most of the literature I've read post-Carnap (1950s-2000s) probably has this backdrop to the conversation too. I just don't get it.

Sorry I don't have a more concrete objection. I just genuinely don't get it – it doesn't compile or register with me as true, false, as anything, really. Which is an issue with me, but still.

And again, I don't have an issue with metaphysics – Plato, Aristotle, Kant, Hegel, Heidegger? I understand them in that order (in decreasing order; idfk what Heidegger is saying), and I think it's valuable to at least analyze and see why they said the things they said and understand their frameworks. Something with Naming & Necessity genuinely just doesn't click with me.

Also, IDC about general modal logic – I know it's useful in distributed systems and model checking, but I care more about the philosophical aspect of it, not just "is this a useful tool or not".