It’s interesting, and I don’t know enough about it to know how it should be working, but in the UK any time you publish a book or magazine (professionally), you are required to provide a copy or copies to the national collection (it’s the law, and they have “book police” who monitor and send you emails until you do). Seems like if academic writing isn’t the purview of this law, we need a new institution who does cover it with the same zeal.
(I realise this is a UK specific institution, but I’m aware some other countries have similar setups, and maybe we should have a global one for all academic literature!)