I will bite again msjinks
We have entire networks of thousands of people traffickers shipping people here through all channels, not just 'the boats'. They are providing a full service including advice about the legal loop holes, and other ways to gain full rights to remain. They have a high success rate, it is amazing how many of them just happen to be persecuted gay/trans men for a while at least.
Additionally, we have millions of 'students' and their families that have stayed here beyond their visa requirements, and have no intention of going home.
You can legally run a 'cash only' car wash and 'employ' people to work there from anywhere with visas, and they last a week and move on - don't you wonder what happens to them all?
The statistics as you well know, are grossly underestimating the number of people living here illegally.
It is an absolute disgrace.