Donald Brown said he thinks "the 'death to all adverbs' rule came more from followers of Hemingway", so I checked Ernest Hemingway's use of adverbs in "The Sun Also Rises" (1926). With 966 uses of "said" and 595 "-ly" endings in the novel (out of over 67,000 words), Hemingway only twice attaches an adverb to a quotative: Mike said languidly. He said slowly. With 235 uses of "said" and 856 "-ly" endings in "The Great Gatsby" (1925), out of over 48,000 words, F. Scott Fitzgerald attaches an adverb to a quotative forty-six times (and also does so often with "said" synonyms). As Robert Archambeau likes to say, "more research funding needed!" (Andrew Shields, #111Words, 10 September 2026)
Note: See my previous post and the two links in it for more on adverbs and quotatives in F. Scott Fitzgerald and Shirley Jackson.