Yes, it lifted everyone. Take a look into any stat on minimum/median salary, standard of living, HDI in any Central or Eastern European country that joined the

Yes, it lifted everyone. Take a look into any stat on minimum/median salary, standard of living, HDI in any Central or Eastern European country that joined the EU against those that didn't - the gulf is massive. Also having lived in one such country before and after joining - yes, the EU helped lift everyone upwards.