If ILL is carefully managed, it should be an efficient cost effective enterprise. Thank you for an interesting opening to this topic. However the capital is owned not by libraries but by the agencies and corporations which own the rights to the information. Rather, the money should be given directly to the user. Budget controls would still be available if the money is given in the form of negotiable vouchers which users could exchange with each other, as well as use to purchase information directly from the owners of the information.
Libraries serve, in the information marketplace, as value-added distributors and agents.
I think that these conclusions are implicit in the question posed. They go beyond the frame of interlibrary borrowing and lending, and for that I apologize. It seems to me that, in order to limit the question to interlibrary borrowing and lending, we would need a further qualification on the question. I think she make some well-informed points. In that discussion, many seem to think publishers will get into the business of selling direct to libraries or users.