I'm the kind of person who almost always buys the "deluxe" version of a game because it bothers me a little to have content that I may never have access to. I realize that companies take advantage of that by offering crappy bonuses that aren't worth the money, but since I often wait until games are pretty deeply discounted the actual difference in cost is often very small and I don't mind paying a couple extra bucks for costumes I may never use, or more than a couple bucks for substantial DLC additions like you might see in an Ubisoft game (I am particularly fond of the Far Cry series' tendency to include remastered versions of whole games.) Back when themes were a thing on PS4 I didn't mind throwing in a buck or two for a cool theme, though I felt they were better as pre-order bonuses.
The recent, trend, however, has been to focus on digital art books and OSTs. These have gotten me to change my ways and start ignoring most "deluxe" versions because they seem entirely useless to me. First of all they are ridiculously easy to pirate and any truly cool art or music will make its way to the Internet anyway, sometimes in legitimate forms too like promotional art on the company's website or the OST as an official release on Spotigy or Youtube.
Secondly I don't even WANT to pirate them, and have never attempted to do so, because they're pointless anyway. I'm nto going to turn my console on to listen to an OST and I'm even less likely to do so to view some digital art. A couple games like the Medieval remake have come with digital comics, which I did download and look at, but it was a very underwhelming experience to say the least.
Who are these things for? Are they just so easy to make that the people who buy them compulsively make it worthwhile? Do enough people not even bother looking at what a Deluxe edition includes that it's worth the extra sales? Is there an actual audience?
Maybe turning your PS5 on just to listen to a game OST is more popular in Japan (a lot of games that do this tend to come from Japanese publishers) but I really don't get who the audience is. Why not just listen on Spotify or Youtube?
In conclusion....BRING BACK THEMES SONY, YOU COWARDS!