I agree with you 100% on your assessment of what can be known, but I think I disagree nearly as strongly on your assessment of the humanity that springs from attempting to know it.
To exist in the state you describe - with neither start state nor isolation level measurable in any tamper-proof way - and to yet still dedicate one's life to observing and pondering the complexity of the resulting cosmos is, to my eye, laudable and beautiful.
Where you see hubris, I see humility. Everyone who attempts to expand the corpus of human understanding of cosmology knows that the endgame is somewhere short of perfection. And yet they are inspired to carry on. It seems to me that matters of state, economics, medicine, technology, and many other fields will benefit from a similar disposition.