Why did Peter Jackson change the whole hobbits around, in the book azog name is only mentioned once in the book kwa Gandalf, plus azog son bolg becomes ruler after his son dies

My guess was he wanted zaidi villains with actual identities and personalities than just Smaug at the end. In the book, the orcs are just bila mpangilio orcs. He probably thought it'd be zaidi interesting to give them names and backstories, so he took stuff from the appendices of Lord Of The Rings. And he probably kept the father orc alive to get another villain.