I know I seem to mention Steven Wilson a lot, but I follow what he does and says, and he had this to say in an interview, which I find pretty relevant: he cannot understand why some bands he admires, who put out great music - he mentioned Radiohead specifically as an example - do not take the trouble to do album packaging that enhances the product, rather than just slap something together. This is more important now than it ever was. In the 1960s you would have bought the latest album from your favourite pop group, irrespective of what the cover looked like, because buying it was the only way you could have the music on hand to listen to when you wished. In 2018 nearly everything is available on Spotify or some other streaming service, The music is available, that is. Why would someone who does most of their listening on Spotify shell out money for a physical copy, unless it was because they wanted the whole package - cover art, sleeve inserts, lyric sheet etc.?
People like Taylor Swift and Ed Sheeran probably sell most of their music in digital form anyway, and sell enough of it to not care much about physical sales. A band like Radiohead, though, probably misses out on a lot of potential extra revenue from physical sales, because people see the CD cover of the Bends and think “Why bother buying that when I already can access the music on my device?”