Sorry for my confusions, though all did have families back home, so may of been a factor or some tax aspect perhaps as I didn't delve. Though did recall reading an article upon the bbc (though had no luck finding it), but that may of been over 10 years ago knowing me at times.
I think, can't remember exactly, the legislation was introduced in 2007, I never had to pay any taxes in Poland while working in other EU countries, I filed a zero tax return in Poland only once, as the taxes have been paid in the other EU country.
There are edge cases where one still falls under double taxation but they are regulated by respective country's tax treaties. Details in Polish: https://europa.eu/youreurope/citizens/work/taxes/double-taxa..., list of treaties per country: https://ec.europa.eu/taxation_customs/individuals/personal-t....