Even very small diversions of massive flows have massive outcomes.

Page-rank / citation / querying works as a signal if the direct benefit of the action to the person doing it outweighs the aggregate gaming incentive of it.

If it's averaged over a large enough population, then the individual action matters less and less, and the incentive to game in non-structural ways goes down, naturally.

This averaging over a massive stream making it more resilient to gaming is one of the benefits of massive query streams.