Some librarians swear by the Dewey.
Me, I prefer the Library of Congress system.
(I have yet to ascertain whether preference is guided by when the MLS degree was earned, or by what system one’s first job used.)
Back in the Dark Ages, in my college days, I spent a lot of time working in the university library. I was told then that the selection of LC vs Dewey Decimal was based on the number of books in the total catalogue. Makes sense, as LC is waaaay more granular. With it, you get a place for each individual book.
Keeping the books on the shelves in the right order with LC was bad enough. I couldn't have imagined the task with Dewey.