The Importance of Sincerity in Art

Harold Bloom was dismayed at how certain writers, certain key touchstone literary artists were being excluded from the canon due to identity politics. Would you agree with Tolstoy that sincerity is a staple of art or not and if so why? Keats said in a letter when he watches a sparrow outside his window picking through the gravel he participates in and picks apart the conditions of that sparrow's existence it's kind of that roostian idea that we're corporeal envelopes with things to be filled up by other people.