Yeh forgey, I think you focus on the minority migrants, the ones from places with failing governments and economies. They make up a fraction of all migrant intake. Let me tell I know a lot of people - second/third generation migrants traditionally from cultures where large families are normal. When they have settled here and start to work and understand the cost and demands of raising kids in Aust., most cringe at the thought of more than 2 kids - maybe not that different to you.
When they see that life in Aust is increasingly demanding both parents work, it become much more difficult to have 4-5 kids like people they did in there old country, where most of the time they live a more subsistent lifestyle and large families can assist that. Not to mention the lack of opportunity to work in those countries affords them more time and energy to bonk.
Just look at the previous migrant waves from Italy, Greece, Balkans, South East Asia. Ask the second generation onwards of people from those migrant waves how many kids they’d like to have.
