The problem I have with modern philosophy is exactly what you say, that for any interesting argument, it "has already been said by at least a few other people and been refuted counter-argued or otherwise discussed".
And that is a problem - what I'd expect from the practitioners of philosophy is to give a concise summary of what exactly is the current state of art answer. Given all that discussion, does the argument make sense (and thus the refutations have been found wanting) or do the refutations prevail?
Okay, there are some topics that are still highly up for debate, or it's acknowledged that the answer must be subjective (as some of the ethical debates do) - in that sense, just make a summary of the strongest currently known arguments pro and contra.
Discussion is a process for getting to results, but the discussion is not a sufficient result by itself - where are the conclusions? Such discussions are a tool for people within a field to produce the results, but the value of the field is limited to what is the outcome of the discussions that can be provided to practicioners of other fields, the final results that they can use in their reasoning. Where is the truth that has been found? Okay, it may be partial, or refuted in future as we obtain more knowledge, but up to our current knowledge, why doesn't the field provide the results of that discussion, removing all the refuted arguments (possibly moving them to a "FAQ list" of "yes, we've thought of that objection and it doesn't matter"), and summarizing (with fine-tuning, improvements and clarification, instead of expanding with more and more comments) the arguments that have been confirmed as irrefutable since Aristotle.
Instead of that, the philosophical community tends to provide all the historical discussion and pretend that that's a satisfactory result of research - it's not. We don't read Newton's Principia and comments of other authors on that to understand physics, we have resources that summarize all that's valid in Principia, that remove all that's not valid in it, that augment what could be improved, and make the original work obsolete for study unless you're a historian. The relationship between Principia and Kepler's findings is interesting from a historical perspective, but orthogonal to the actual content. Why then are we reading e.g. Kant's response to Hume instead of producing (Back then! I'm not talking about a textbook for students, but as something the research field would be expected to write for themselves right after Kant's publications) something like "Hume - revised" where all the Hume's opinions are mercilessly edited (because we shouldn't care about all Hume's opinions, but only those of his opinions that happened to be correct), removing the parts that have been refuted, leaving the parts where Kant's response was found insufficient, and replacing the parts which Kant was able to clarify with Kant's words, with a footnote to attribute authorship. If a refutation matters, then the original work should be altered (Where is the "Nicomachean ethics, 114th revised edition"?), and if a refutation doesn't matter, then you shouldn't be ever reading it in serious literature without a preface noting "this is a historically interesting but erroneous argument, counter-refutation in page xyz). The discussion is something that should matter only for those making new philosophy, but not those studying and applying ("consuming"?) the existing philosophy.
Instead https://plato.stanford.edu/entries/kant-hume-causality/ states "There is no consensus, of course(!), over whether Kant's response succeeds, but there is no more consensus about what this response is supposed to be". Emphasis on the "of course" is mine, because I find that part informative, illustrative, and outrageous - if this is currently considered a reasonable state of art description, then the field seems to explicitly acknowledge that it's worthless, that it's not even attempting to provide any actual answers out of these discussions.