The point is though, that if enough people do the same study, and only the positive results are published, you're increasing the odds a lot of getting a positiv

The point is though, that if enough people do the same study, and only the positive results are published, you're increasing the odds a lot of getting a positive result from someone. That's why companies often finance studies in their drugs. If enough people study their drugs, something which doesn't have a measureable effect, might have a measureable effect in some of these studies. At which sample size this becomes reasonable is a good question though.