Isn't that a problem in itself?
Not really. That encompasses scientists of every discipline, and thousands of different research topics. Scientists tend to be very familiar with the literature in their field, related to their research. So the chance of unearthing fraudulent papers is actually pretty good.
I should point out that it is impossible to know how many papers are published every year; I saw an estimate of 1.2 million per year. The point is that the number of fraudulent papers is a tiny fraction of all papers.
The point is 1.2 million papers per year is about 900,000 to many. You cannot look at me in they eye and tell me there are 1.2 million “discoveries” per year.