Another way to bootstrap this immensely desirable "spotify for news" model could be a platform (trusted third party) for mutual co-subscriptions. Subscribe with publication A, also gain access (metered behind the scenes, redistributing some predetermined part of the subscription fee according to measured consumption) to otherwise equally paywalled publications B,C and D.

But something like that will only happen when attractiveness for publications is maximised, which requires, amongst other things, that the platform avoids consumer facing lock-in or even just branding, because that would make publications (rightly) fear that they hand over whatever pre-existing digital subscriptions they already have to an exploitative intermediary. This in turn pretty much rules out the VC model for starting the platform, since eventually becoming exploitative is a required ingredient of the risk equation. But I see no reason why this could not work as a cooperative, because all the platform marketing would be directed at potential members. Consumer marketing, something in which a cooperative would tend to be inferior to a metrics-driven VC project (by a wide margin I suspect), would be left entirely to publications, who subsequently get to "own" the subscriptions they pulled in. Important design parameters would be the ratio between pooled and unpooled fees and the exact rules about weigh and how much content member publications would be allowed to keep exclusive to their direct subscribers. Outside of implementation, the biggest challenge would be to convince publications that few people would ever subscribe directly to multiple channels (how many people had now than one daily newspaper?) and that therefore, the content made available to subscribers of their peers would not cannibalize potential direct subscriptions very much.