Poland receives subsidies in exchange for opening its market and for following the tax and labor regulations. All the poorer EU countries do. In the end, it is Germany that benefits the most from large markets for its goods. It would have probably been way more beneficial in the 90s for Poland to have a more closed economy, emulate South Korea and become a "small China in EU" with cheap labor and factories. I believe it was a grave mistake of the Western Europe to invest so much in producing high-tech goods in China, when during a period of 1990-2005 they had access to cheap and educated labor force close in Eastern Europe. You should never transfer your strategic industries into countries that you cannot influence or control.