it takes work to reach them, but there's still an audience out there. trust me.
I believe you. My own max book ownership age was probably ~28. Ever since then, I've been trying to get rid of books, not acquire them. I'm now down to ones that I retain mostly for sentimental reasons.
Interestingly, when I was trying to shed books, I found that I could not even give them away. Libraries wouldn't even take them. Sad to say that I actually threw away many boxes of books.
I know that many of us will die with piles of books that our heirs will have to deal with. Just know that it won't be an easy task for them, and most of those books will probably end up in the trash.