I feel like New Zealand and Australia are the two least suited countries for this idea. New Zealand is very mountainous and subject to earthquakes and volcanos

I feel like New Zealand and Australia are the two least suited countries for this idea. New Zealand is very mountainous and subject to earthquakes and volcanos. Australia is half desert. I wonder what the best location to concentrate the world's population and agriculture actually would be. My guess would be North America, India, or China.