Public posting, public comment has been tried and the results are not good. Authors rarely feel the need to revise in response. The articles tend to be full of spin. The idea seemed decent, at first, but never worked out in practice. Some major OA publishers tried to say that folks needed to read the comments to get context on what may be wrong with the paper; however, many of those platforms did not account for the need to archive the comments along with the PDF so the context and "review" got lost.
Public comment also does not mean that experts with knowledge in that subject area are going to comment. The vast majority of researchers just read the abstract without looking deeper. They certainly do not have time to read the whole article, the comments, or comment on it themselves.
I ran a pilot on this concept for 3 years. The pilot had every article using public posting and commenting. The editors also used traditional peer review. They compared the results and traditional peer review was better and more comprehensive every time.
It's a nice concept and may it work in some fields, but I work on the medical side and it fails as a concept. A doctor who sees patients, teaches and conducts research does not have the time to spend here and the sheer volume of articles will mean that most never seen any comment or review.
I don't have your experience with the trial so I will trust your results there. But in general I think these issues speak more to a mismatch in expectations than failure of concept.
Archiving comments properly is a technical concern and solvable.
As for the readers looking at just the abstract (and, I assume,
trusting it) -- frankly, that is an issue even if the research is peer reviewed. The replication crisis, not to mention the outright fraud crisis, is fully exposed at this point. I'm not sure what use case you imagine -- is it doctors reading the abstracts and then treating patients based on this? That would speak to a need for an intermediary between research and clinic (like UpToDate) even with peer review.
Or if it is researchers just reading the abstract, for purposes other than evaluating if they should read further or not...then I am not sure I trust their scholarship.
But yes, under a "public post, public comment" regime, abstracts are going to be less trustworthy. I think this is a
good thing, not a bad thing, because it means people stop trusting things they ought not to trust just because it has the peer review stamp.
Another way to phrase it is--peer review is designed to strengthen the "
weakest link", the weakest papers. But peer review isn't an effective tool to prevent them, and can make weak links look strong because they have a seal of approval. In a more public regime, the job of vetting and compiling all this information for end users who don't want to read the papers can be done systematically rather than by ad hoc committees.
Unfortunately I am not sure you can capture how the dynamics will shift with a pilot study, because it (hopefully) will lead to a cultural shift in how practicioners engage with scientific papers. But that cultural shift is desirable anyway.