Why is it that Australia and NZ became technologically advanced and wealthy?

Australia and NZ's is wealthier then Papua New Guinea because Papua New Guinea has less resources and also has less tech stuff. One thing about the PNG's is that they don't have much clean cloths and they probably have less then 10 pairs of cloths to wear. The Australians and the NZ's have more then 30 pairs of cloths to change in probably.

 Here are some some difference about the NZ's and the PNG's, the Australians and NZ's are mostly white and the PNG's are white, the Australians and NZ's are not so poor and they they can buy food from outside because they have more money then the PNG's. The PNG's are kinda poor try to get food outside were they live which is by the woods and they cook it.The Australians and the NZ's have more bigger lands and islands but the PNG's have way smaller lands and islands. Maybe one of the same thing about the Australians, NZ's and the PNG's is that they are both safe countries nothing really bad happens because maybe they are all peaceful countries.

cia.gov

Maybe also PNG might become a rich and wealthy country in a few days because some countries were first poor and now they are quiet rich.