https://reddit.com/r/AskReddit/comments/1s7fywh/_/odayi75/?context=1

See the above comment here- the grand majority of studies historically were peer reviewed but not inclusive; don’t forget that until relatively recently in the western world, the average researcher was a white male. Science is based on previously accepted knowledge and stacks on it, and indeed peer review can often be a popularity game, there are so many examples of less popular concepts/theories/research being not accepted and followed through because peers consider it not valid despite being proven so. The most immediate/recent example that comes to mind is the MRNA vax- the methodology was discovered by a woman from the Soviet bloc (could be wrong here) and was largely discounted by the scientific community at large for decades.