Daytime running lights are a PITA. I have been blinded by them early morning when coupled with the sun low in the sky. IMO they serve no purpose on a brilliantly lit day except to add to fuel costs by loading the alternator and contribute uneccasary light where it's not needed.

I don't know how it is in australia, but in europe we use dimmed headlamps for daylight, and I have never been blinded by them either at night or in day.
As for the purpose, the main contribution if for pedestrians, beacuse you can easily identify which cars are running and which are not, but most of everything it helps a lot with guessing the distance and speed of the oncoming car.

 

Just Chrysler in North America uses undimmed high beams for daytime running lights.
It is their way of advertising their cars and trucks. I hate them for blinding everybody.