In my apartment we have ~2,500 books (so says LibraryThing). They take a wall 4m long of floor-to-ceiling bookshelves in the living room, another 2 bookcases (double-width Billy), and another wall in the office (2m floor-to-ceiling). They also overflow to an office at the University and various stacks around the apartment.

The thing is though... we've read nearly all of them between us. We probably have only 2% unread at any given time. That's still a good stack of options to read next, still a whole shelf we haven't touched.

For time, books feel denser and richer compared to TV and most films. Only music and poetry feels as dense and rich.

I wish I could say that there was order to our shelves and there was once several orders! Some parts are by publisher, some parts by theme! Mostly we buy books and add them where there is space.

As to wishlists, we purchase when we see things we want and we're not using wishlists. The things we order tend to be obscure and rare - not valuable, just obscure - so if we don't get them at the time we might not see them again. There's something nice about this... books arrive constantly, and that means there's always something exciting to discover.

Edit: https://www.librarything.com/ is invaluable. We initially got it to help us catalogue things for insurance purposes, but it proves extremely helpful at preventing us from buying the same book twice. Most recently published books only need their barcode scanned or ISBN entered, only the old ones need manual entry.