Wikidata items have none or one statement. To put it bluntly, we do not know what they are about.. They could be a human, a settlement, a meteor anything really. What we do know it that there are articles associated with them.
Things are improving; statements are added all the time and the improvement shows both in percentages as in absolute numbers.
Statements are important; they help identify items that can be merged, they provide connections to external sources and, they provide the information for use in Wikimedia infoboxes. Currently Wikidata has some 15 million items and 4,437,324 items have no statement. Once items are identified as humans, Magnus's games includes four games that help identify subsequent statements.
The trick is to find items that give a clue that all the items belong in a specific category for instance "born in 1905" indicates that the item is likely to be about a human. Once an item is known to be "human", it becomes easy to link it to all kinds of other statements.