That's actually exactly correct. Peer review is supposed to characterize the research in terms of quality, not validate it. Otherwise, those peers who validate it would practically be co-authors.
It's a system built upon honesty. A dishonest person is obviously going to take advantage of it. Really blatant things are caught in peer review, but sneaky fraud will definitely slip through.
> Peer review is supposed to characterize the research in terms of quality
Fraudulent research would obviously not be of the desired quality, wouldn't it?
> It's a system built upon honesty.
But if the purpose is to characterize the research in terms of quality, this can't be right. Since fraud is known to happen, and there are known to be incentives for fraud, any process that claims to judge the quality of research would have to have some way of checking for fraud.
I think you're misunderstanding what I mean by "quality" in this context. It's not quality as in something like meat, it's quality as in "a quality education". Does it go above and beyond vs. do the bare minimum to address the scientific question proposed by the authors.
Something can appear to be of very high quality and yet still be completely fraudulent. This occurs in countless fields; art, counterfeit money, deepfakes, etc.
Scientists are attempting to address fraudulent research in other ways, but peer review is not the best means for it and it should not be thought of in that way.
It's a system built upon honesty. A dishonest person is obviously going to take advantage of it. Really blatant things are caught in peer review, but sneaky fraud will definitely slip through.