Re-search means literally “search again” what others thought they have done their best to make sure there are no stones left unturned.
It happens all the time that experts in the field think it’s done and there is nothing more to dig in there and start focusing on something else.
Except that the last person finds an abandoned yet kept remained key stone unturned and makes a major discovery.
It happens all the time.
This is also the reason you can not dismiss any nonsensical stories or ideas that seemingly defy logic yet known to be scientific .
The significance of the study is a part of the introduction of a thesis/research. It should determine who benefits from the study and how that specific audience will benefit from its findings.
The significance of the study could be simply reflected by the following two questions: Why should my study be published? What significant scientific contribution is my study making to my field of research.