This question is not so easy to answer because the calculation is very complex and each race would have to be considered individually. First of all, it is important to understand that Elo points are only re-distributed between drivers after a race. So in order to gain points, other drivers have to lose some.
The system calculates a target position expected by the driver in the race based on their own Elo in relation to the Elo of all other drivers. If the driver achieves a better target position, they will gain Elo points, if not, the driver will lose Elo points.
If a driver's Elo is relatively high or low compared to all other drivers, it is expected that they will have a correspondingly better or worse target position.
In very balanced splits (e.g. Elo differences < 250), you have to finish the race in the upper half to gain Elo. Drivers who finish the race in the lower half will lose Elo.
With increasing Elo differences within a split, the expected target positions of the individual drivers also vary more, which means that such a general statement can no longer be made.
Furthermore, it is important to know that only the finishing position of the race is taken into account for the calculation of the Elo points. The places won or lost in the race in relation to the starting position is not relevant.