Kasey on this question of "the perfect" in poetry (which I expatiated on here recently).
First of all, if you found the perfect poem, this would not necessarily preclude further interest. Not simply because there might be an enormous number of perfect poems out there, but also because perfection in a poem would prove to be inimitable : it would be a perfection of form & expression unlike any other.
Secondly, I think the search for perfection is implicit in the work of the critic. Eliot, in Four Quartets somewhere, quoting Mallarme, wrote of the poets' vocation as "to purify the words of the tribe". The exacting effort of discernment, differentiation & judgement undertaken by the critic is complementary to that vocation. Through the critic's investigation into what exactly it is (the poetry under consideration), all kinds of literary faults are examined & evaluated (dullness, superficiality, irrelevance, unoriginality, faulty diction, garrulity, bathos, parochialism, ignorance, pomposity, etc. etc.), so that, by comparison & analysis, the really excellent work of a place or a period stands out.
This is the technical side of criticism, which is just as essential as are the appreciative, imaginative, synthetic, "analogical" elements of readerly interest.