We need to move away from the idea that there is such a thing as 'settled knowledge', because as you suggest there is always something else to uncover. Our knowledge is fallible, never settled, there is always the possibility to find and correct errors.
All we have is our current best explanations/understanding. We use them to make progress until we find a problem with it – something it fails to account for, something it makes an incorrect prediction for etc.
Then, we attempt to conjecture new explanations which solves the new problem while still accounting for all the useful aspects of the old theory.
That is knowledge creation, and also progress.
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And if our forefather/mothers ran away every time they encountered a "swamp", we wouldn't have that. If you ask me the philosophical accomplishments of this era are minimal, if not negative...let's hope there's no penalty for that, for us or our children (say, the effects of climate change on a species who is unable to act).