While they may seem similar at first, Shelves and Lists serve different purposes on Blackauthored.
Shelves are designed to help you organize and track your reading journey. Use them to keep track of books you’ve Read, are Currently Reading, Want to Read, DNF’d, or organize books into custom shelves that fit your reading habits.
Lists, on the other hand, are meant for curating and sharing collections of books around a theme, topic, mood, or idea, i.e. MMCs who are down BAD.
In short:
Shelves = personal organization & reading tracking
Lists = curated collections & recommendations