What's clear is that Poles understand more English than they can speak, or feel confident to speak.
I'm sure this is the case in many countries; it's certainly the case in Hong Kong, for example - while English is an official language there (unlike in Poland), many people are not confident to reply in English, but often understand the basics (and can reply by typing a price into a calculator, as one example, lol).
Personally, I have no idea how well English is spoken in Poland, because I've never spoken English in Poland, except to a few lost foreigners who needed directions. On the few occasions where passport control have opened my UK passport and asked me a question in English, I've always replied in Polish. Few of my relatives in Poland know much English, though - those who stayed, never felt the need to learn. Those who left, seemed to have learned so they could