Lisa Janicke Hinchliffe, in a keynote address [repurposed as a Scholarly Kitchen post](https://scholarlykitchen.sspnet.org/2020/04/07/seeking-sustainability-publishing-models-for-an-open-access-age/):
> From the library perspective, The Big Deal is typically seen as no longer sustainable. One must ask then if transformative and pure publish agreements will suffer the same fate. In my view, it seems impossible that they will not.
The whole [talk](https://scholarlykitchen.sspnet.org/2020/04/07/seeking-sustainability-publishing-models-for-an-open-access-age) is worth reading—Hichliffe provides a taut historical overview and some definitional anchors. She's as unsure about the future as anyone:
> All parties are seeking sustainability. But, ultimately, the question seems to return to the query—sustainable for whom?