Per Pippin, writing in LSE Impact on a Diamond Open Access Fund:

Read-and-Publish deals are likely to be short lived; they were, after all, supposed to be ‘transitional deals’. The public money that has so far been spent on these deals could be better invested in this kind of fund when these deals come to an end. This would be truly transformative.

One can quibble with the funding figures that Pippin floats—and with his breakdown of costs. But his core point, that collective funding is the only road to OA that doesn’t exclude authors, is unassailable. The toughest nut to crack is funders’ habitual (and, in some cases, legal) commitment to single-unit, per-work support.