The benefits of diamond are not crystal clear - Research Professional News

"...At 56 per cent, the proportion of open papers has more than doubled since 2018, when the combined total was just over 25 per cent. That represents a trebling in the total number of papers published this way.

This trend, however, has left many policymakers and advocates of open access unsatisfied. They are now promoting diamond open access, where papers are free to both authors and readers, and journals are financed directly rather than via subscriptions or publication fees, by consortia of institutions, grants or other sources.

But there remain misconceptions and blindspots in the debate around this approach to scholarly publishing. A realistic assessment of the sustainability of diamond open access needs an agnostic assessment of its total costs and viability as a business model.

Without this, the risk is another cycle of high hopes, unforeseen consequences and disillusionment..."