Yes, it's happening: The Collection is shrinking. There was the Great Weed of 2012 and the Rethinking of 2021, not to mention the Rise of the eARCs and the General Tidying of 2017... but there are fewer books. And, also, fewer bookshelves.
Before the Great Weed, The Collection and Mt. Bookpile were too big to fit comfortably on the eight 8' bookcases, the six 7' bookcases and the three 4' bookcases. Things were sorted into so many genres: Children's/Young Adult, Mystery, Speculative Fiction (which included all Science Fiction and Fantasy), Legal, Political Science, Humor, Horror, Cookbooks, French, Literature, Popular Fiction. Reference, Women's Studies and History.
After the Great Weed, there was room on the bookcases, but it wasn't until I left the townhouse that two of the 7' bookcases left to take up residence in two other homes, helping colleagues house their collections. The different genres stayed, mostly because Move One required that The Collection remain boxes (Mt. Bookpile was on the few shelves that fit into that home).
Move Two brought The Collection out and back onto shelves. There was a General Tidying, and the genres shrank to Children's/Young Adult, Mystery, Speculative Fiction (which included all Science Fiction and Fantasy), Humor, Horror, Cookbooks, Literature/Fiction and Non-Fiction. The 4' bookcases were repurposed, serving as organizers and home office supply holders. And then, just about a month ago, I embarked on the Rethinking of 2021, compelled by Move Three.
I'm on the other side of that move (mostly), and none of the 7' bookcases are here; of the remaining four, three are in off-site storage and one fell apart while being moved. There are enough empty shelves to get rid of one of the 8' bookcases (which I am not going to do! the Mantle Cats and some memorabilia/knickknacks/photos can be displayed on those shelves), and one of the 4' bookcases is also about to bite the dust and will be allowed to expire as soon as additional shelving for the linen closet can be purchased.
Yesterday, I got seven new books. All were eARCs, courtesy of publishers. I still purchase print, but usually only books that I know I'll re-read or books that Thing One would also like to read. And even though I've just moved in, Move Four is in the back of my mind due to my impending retirement (by 2024/5). What will The Collection look like then?