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.