Faced with a major downsizing I shocked myself by removing recipes I would actually cook from many, many books and filing them in plastic folders according to main ingredient. The remainder of the (what felt like vandalised) books were recycled. Bulk was reduced by 90%, the folders fitted into our downsized space. 13 years on I don’t think about the books, just enjoy re-visiting the recipes.
Other books from several large bookcases were either recycled or went to a local charity book shop. Those from my professional life were mostly sold, I kept three. Mr C wanted none of his.
I kept the handwritten recipes from my mum and ma in law. I don't cook any of them now but will never part with them. We also kept several childhood books dedicated to us by the givers, bibles with family notations along with professional books belonging to Mr C’s dad. A bit of family history. All fit on one shelf. Now we mostly read library books on our iPads thanks to library remote access. Sometimes we buy books from charity shops and recycle them in the same way. It’s worked for us, we have the books with personal meaning and don’t miss the rest.