Is philosophy actually hung up on that? I assumed “what is consciousness” was a big question in philosophy in the same way that whether or not Schrödinger’s cat is alive or not is a big question in physics: which is to say, it is not a big question, it is just an evocative little example that outsiders get caught up on.

That's just one example sure, but yes, it does still take up brain cycles. There are many areas in philosophy that are exploring better paths. Wheeler, Floridi, Bartlett, paths deriving from Kripke.

But we still have papers being published like "The modal ontological argument for atheism" that hinges on if s4 or s5 are valid.

Now this kind of paper is well argued and is now part of the academic literature, and that's good, but it's still a nerd snipe subject.