I think op is arguing that somewhere libraries should be able to have reasonably fixed budgets and not have this constraint, though more aggressive legislation

I think op is arguing that somewhere libraries should be able to have reasonably fixed budgets and not have this constraint, though more aggressive legislation that weakens publisher's rights. I think it's possible with things like reducing copyright durations entirely to get a healthier public domain offering instead of books written by people whose grandchildren or even great-grandchildren have died of old age still covered by copyright. I actually just checked and I think there's no infinity copy ebooks on Libby at all; even books that are long since in the public domain have a fixed number of copies to borrow that presumably the library is still paying someone for per-copy.