I agree with everything except that the I think the paper, and other papers in general, should be judged on their merits alone. The credibility of the authors should not influence how the paper is judged.
Credibility is one heuristic that let’s us figure out what might be worth investing time into, since your answer cannot be “everything”.
With respect to publishing, there is a significant volume of work, and we should be able to keep up with it long as people review as much as they publish.