It didn't grow quickly between 1990-2004, did it?
Of course it did!
Compare the rise between 2004-2019 with 1989-2004, and you have your answer.
Polish GDP 1990 - 65,98 billion USD.
Polish GDP 2004 - 255,1 billion USD. 386% growth
Polish GDP 2005 - 306,1 billion USD
Polish GDP 2018 - 585,7 billion USD 91% growth
I am not against the EU, quite the contrary, I think Poland benefitted from her membership, but this argument doesn't stand.
We would need to transport ourselves out of Europe into some far away ocean....
They still need to cross the Mediterranean to get here, don't they? And believe me - they would find a way to settle in Japan IF Japanese laws allowed them to do so, but they DON'T.