Ugh. What is it with the state of desktop ebook readers?
Gnome Books: Dead.
Calibre: Clunky, heavy, ugly.
FBReader: Went closed-source and mostly abandoned Linux.
Bookworm: Poor filtering, poor sorting, paged library, only had translation updates in the last year.
Foliate: No real library management. No sorting.
Librum: Flatpack-only (also, C++ and QML). Appears to depend on a server. Has "AI tooling".
Lector: Crashes on launch.