I'm quite confident that scientists (and hopefully regulators) read the source journals.
> I want to be able to trust in institutions to make informed decisions to improve environmental factors that require collective action.
And you want to be able to do that without the public being informed enough to even care and hold them accountable for that? Why on earth would a politician make a costly decision like introduce regulations that makes plastics a lot more expensive when the public literally has no reason to want such a thing?
> I don’t think informing citizens about danger so they can demand policy reform is the actual purpose of The Guardian article
The "actual purpose" of any published information is pursuit of incentives, so sure, you're right. Guardian publishes this article to get ad views. The journalists publish it to increase their notoriety and hopefully get a promotion. But the same applies to the information published in journals. The "actual purpose" of putting it there is to increase the researchers' stature in the research community.
> that’s a fairy tale about how the system actually works.
Not really. The entire system, insofar as any system works whatsoever, is to co-opt people's own imperfect incentives (like pursuit of ad clicks or personal notoriety) to produce positive externalities (like an informed public). This is literally every stable system. A company co-opts people's personal incentives to feed their families to produce the externality of a profit-generating corporation.
Pointing out that people and institutions have imperfect incentives and therefore the system is broken, that is the fairy tale that people tell themselves to avoid engaging with reality as it exists.