Why would it be hoarding if I had thousands of shoes or socks or plates or sad-eyed Keanes but not books? Is it hoarding to have more than a functional number of friends? Obviously not. Books are as various & necessary ~ the friend you see once a year to go to the opera, the same-time-next-year baseball game goer, the friend you talk to every day, the friend you call to share good news, the one you commiserate with about relationships. You can have books, like friends, for any or all occasions.
And even though I own more books than I can ever read, I buy or check out more all the time. I wouldn't buy a pair of shoes I didn't intend to wear, but I buy books all the time knowing I'll never open them. If that's any equivalence to a gambling (say) addiction, I totally get it. It's the moment of acquisition, the rush of the bet/purchase. What comes after is a different emotion entirely.
And yet, if I had to, I would walk away from (almost all of) my books. I have them because I can, because I don't have to walk away (yet).
A home without books is a home without laughter, without love, without curiosity, without friendship.
I do try to keep them on the shelves & not spilling over to the floor or chairs. It might be time for a wee purge to get back to that status. Sigh.