it will as ever be the most vulnerable employees who suffer
Partially because anyone that had a choice has already left. The ones working in corpo jobs can simply apply for transfers elsewhere after a year of work, and other specialists will easily find work abroad.
We can see now that the 2% retail tax is planned to hit every single business with a turnover of 12 million PLN a year regardless if it's online or offline. That means that Polish webshops have no chance against foreign retailers such as iperfumy.pl, Zelando.pl and asos.com. 12 million a year isn't much money, as it's based on turnover. A lot of even smaller online retailers will hit this barrier - and when they do, they're going to take up and move the business to the Czech Republic or Slovakia on paper. The goods will still be physically posted from PL, but they're going to pay Czech/Slovak social insurance and taxes and the 'ordinary Polish man' is going to lose his job.
Meanwhile, today, the CEO of Auchan in Poland will order his finance director to find ways to recover the money lost to the government. That means squeezing suppliers, expecting higher productivity (did you know that cashiers are judged according to their 'scan rate'?) and cutting numbers employed. All of these things will hurt Polish businesses and Polish people. Obviously - Auchan cannot get away with paying their workers less than minimum wage. But the guy that supplies them... well, if he wants to keep the contract, he's going to have to cut his prices.