you can be properly authenticated but not authorized, whatever it means in the context (something like not competent?) trusted journals are trusted for their competence in filtering crap out, not for being able to prove that authors are really authors.
Sure but it feels like there is some close relation there: proving an author is genuine and proving the author is producing genuinely valuable work wrt some given publication's specific audience.
If one were to build a system along that line, meant to replace prestigious academic journals of today, of course it would be gamed. But isn't the general consensus that the current system already is being gamed and usually at expense of the researchers doing valuable research and the public at large?
The academic system of universities, degrees and professorships already provides a pretty elaborate system for "authenticating" academic credentials, so I don't think trust is really that big an issue. The Journals don't really add any extra layer of effort to find "trustworthy" referees, they just find academics who are already employed in a given subfield who are willing to review papers.
(and in anycase, most subfields just have a couple thousand individuals involved at the PI level, who frequently interact at conferences, went to the same schools, shared an advisor, etc. So there doesn't really need to be an elaborate scheme to verify someones credentials. Chances are two individuals are already aware of eachothers reputations, or at least know some third party who is).
Publication in trusted journals is a major component of getting hired and tenured at universities. There should be less emphasis on this, but it's an attractive option for review boards working outside the field of the person under review.