The reason the G is higher than the rest is actually pretty ridiculous.
Back when the Stratocaster pickups were designed, it was common to (a la an acoustic string set) use a wound G string. Now, because the winding on the string isn't as readily picked up by the magnet as the core, the G string wasn't as loud as the surrounding strings. Thus, to compensate, the polepeice was moved closer to the string to give a louder note, providing better balance.
Flash forward 10 years. It's now the late 60's, and "rock" music has come into its own. To facilitate string bending, many players have dropped wound G strings for lighter, unwound G's. However, due to the fact that it's unwound, the G string actually is "larger" than the core of the wound string, and is suddenly the loudest string on the neck of the guitar. Good thing the polepeices on everyone's Les Pauls are adjustable.
Fast forward 40 years. It's the late 90's/early 00's, and vintage tone freaks everywhere want exact replications of the early stratocasters, including the offset polepeices, which were initially offset to compensate for a string standard that was abandoned nearly 50 years ago.
And Fender snobs call US stupid.
Personally, I arc my polepeices to approximately match the
fretboard radius. Why? Because i tried it, and I liked how it sounded. It's not "better" than any other answer, but I'd like to think it's a little less arbitrary than the way most singlecoils are set.

You may not like this configuration- this is why I prefer pickups with adjustable polepeices, because if you don't like how a specific arrangement sounds, just take out your screwdriver or
allen wrench and you've got a new one.
And it really does make a difference- i was floored how much more "warmer" and "resonant" it sounded when i hit the first chord after making the tweak.
-Drew