There is a tendency to publish and cite studies that show positive results (statistically significant) than negative (null/void) or inconclusive studies
This is called publication bias and citation bias.
A few articles to get people started:
The last article mentions that publication bias a big issue in pediatrics.
"Reporting biases arise when the dissemination of research findings is influenced by the nature and direction of results. Statistically significant, ‘positive’ results that indicate that an intervention works are more likely to be published, more likely to be published rapidly, more likely to be published in English, more likely to be published more than once, more likely to be published in high impact journals and, related to the last point, more likely to be cited by others. The contribution made to the totality of the evidence in systematic reviews by studies with non-significant results is as important as that from studies with statistically significant results."
Bolding mine. I bolded it because it highlights why we should care about publication bias