Recall that Wikidata uses properties to describe items. The more information there is about an item, the better-connected it will be to other resources. This is where your expertise comes in. You may have some depth of knowledge about the topic that other editors don't. You may also know where to research this topic to add more information.
The item "Members of the Legislative Council of Trinidad and Tobago" (Q63345382) was created to fill a structural need (linking people who were members of the council). But it's just a bare-bones item — it has a label and a description, but there are no statements. The lack of statements means that other editors may not understand how to use this item.