[praptak]

Since the phenomenon itself does definitely exist and there is no single word for it (that I know) I am all for using tsundoku for it :)

[mdszy]

Right down there in the other "Book Collecting" articles it literally says:

> Bibliomania (tsundoku)

There very clearly is a word for it. Bibliomania.

[lopan]

Oxford says bibliomania = passionate enthusiasm for collecting and possessing books. It doesn't say anything about whether you read them or not.