I agree. Very often I am in the bookstore browsing, and I can't remember if I actually already have a copy of this particular book (either Kindle, or a physical book, or multiple editions!).

If I could either search by title, or scan the barcode via the app, and instantly, be able to see if a) I own the book or not, b) see if I own a digital copy, or a physical copy (or both 😅), then it would be easier for me to know if I already own this, or if I want to buy a physical copy. Now it's a bit too cumbersome. I can't filter the editions list to show which editions I own, so that is not an option (scrolling through hundres of editions in some books is not an alternative either).
I can click on the "main button" to see which lists this book is on (to see if it's on the "Owned" list, but that too requires too many clicks/taps. Especially if I have 5 books in my hands in the store :D.

If I could, in the main book info (top part, where it has year, number of pages and ratings), see if I own it, and which edition(s), then I could see in an instant if I already own this or not. That way I can avoid duplicate purchases. And this needs to work on the mobile view as well, not just desktop view.