Quartz has an informative article about book delays. Basically, more people want physical books, lumber is in short supply and with COVID, there's a reduction in workers to make paper. Many books are printed in China. Port congestion, lack of shipping containers, a shortage of dockworkers and trucker are slowing the movement of books from warehouses to stores.
For the 2021 holiday season the key is to shop early. Huber said to preorder any books you’re looking forward and be flexible. Remember, independent-bookstores can help customers find a suitable replacement gift if the one they want is not in stock. Most important, they say: “Be nice to retail workers, as we cannot control the supply chain, and the shortages aren’t our fault.” The same advice applies to our library staff.