I certainly wouldn't claim Hemingway was obscure, but I don't see any of those figures undermining my point that the average person in 1926 wouldn't feel the in

I certainly wouldn't claim Hemingway was obscure, but I don't see any of those figures undermining my point that the average person in 1926 wouldn't feel the inclination to read him over more digestible stuff (and the Bible) if they read at all. Sure, the first eight print runs of The Sun Also Rises probably had a total circulation equivalent to the playthrough of some tediously-narrated niche videos on YouTube, and by 1961 when Hemingway was firmly established as a Great American Novelist it had as many copies over more than quarter of a century as Where the Crawdads Sing sells in a quarter, but I don't think you can infer anything much about attention spans from the appeal of literary fiction.