Quality workmanship.
After Spark's comment they showed a slow mo of the release and it was very noticeable how much like a uniform, smooth orb the ball looks after that many overs.
Yeah. This isn't an abrasive pitch at all, there's enough dead grass on it that it won't wear much but with little seam movement. IIRC they've actually made the pink ball harder wearing with a thicker coating recently because in some matches on much harsher pitches it would just fall apart into strips. And remember at Adelaide they have left more grass on the pitch specifically to protect it.
It's something to do with the physical natures of the dyes used and how they interact with the leather. For both the pink and white balls I've seen, it's like it doesn't dye a bright colour. Exposed leather under the bright top coating is either dull pink or light grey with a slight greenish cast. Very worn and gouged balls sometimes end up with their colour worn off exposing a brown leather surface, as if the dye hasn't penetrated (though I've seen some white balls where it clearly has to some extent). Whereas the red balls have a very thin top coat if any at all, and the leather underneath, though much duller in colour than the new ball, is clearly a reddish colour all the way through.
Don't know about the exact chemistry behind it, but read an article once saying the red balls use an 'aniline' dye (I don't think they use actual aniline these days), which is a soluble dye that penetrates and leaves a natural surface. I think it even said the the dark colour of the Dukes ball is because the leather has absorbed the dye leaving not much on the surface. Whereas the pink and white dyes seem to be pigments, and they don't penetrate as much. Not sure if the paint-like coating is just how the dye ends up or if they deliberately apply that. But difference in dye behaviour is why there was such trouble with the white ball losing its colour (and why we now have the silly two new balls rules), and why the pink ball is so troublesome.
In my opinion the pink ball is not really suitable for test cricket because it doesn't polish, doesn't wear well for the spinners and I'm not aware of any instance where it has reverse swung. Combined with the fact the Kookaburra version at least seems to go soft very quickly, it just doesn't leave anything for the bowlers after the first fifteen or so overs unless the pitch is very grassy or you have an Ahmedabad situation where it skids unpredictably.