This is something I’m looking into this year, as I’d like to do something with my photography besides just dumping it on a hard drive forever.
Having printed cheap photo books in the past and acquired some nice ones (from other photographers) recently, I’d highly recommend looking into actual photo book printing services rather than KDP. A good photo book has more consideration than just printing, there’s paper weight and quality, color matching, layout options, and size.
I haven’t chosen a service yet, but this comparison (I have no affiliation with them) is a good place to start on the services available currently:
Best Photo Book Printing Services comparison