Your question gets to an ongoing debate among scholars of The Canterbury Tales with respect to the persona of Chaucer the Pilgrim and Chaucer the Poet. Is the Pilgrim an observant narrator but not particularly bright, or is he, like Chaucer himself, an astute judge of character whose descriptions of his fellow pilgrims are meant to be highly ironic because they depict the difference between the ideal and the actual? The tension between what seems to be and what is, after all, creates the humor in the poem.
If we look closely at a few observations Chaucer the Pilgrim makes, we will see that he is indeed a naïve and limited observer, but in the service of comedy and realism, the observer unfailingly focuses on the pilgrims' attributes that tell us where they are on the spectrum of the ideal and the actual.
When the observer describes the Prioress, for example, he notes that
Her greatest oath was but by St. Loy; and she was called Madame Eglantine. (General Prologue: 120-121)
Chaucer the Pilgrim...
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