You could say the same about Dutch to be fair. 90-95% speak English - I bet that's way higher than in Poland.

As an American, my perspective is that Dutch people speak better English than a large percentage of English people and Americans.

As a Dutch person, I'm very doubtful that's the case, but I'm willing to bet a good ESL speaker is more aware of common grammatical errors than some native speakers. For example, the your/you're mixup makes no sense if you've had to explicitly learn about English contractions in the first place.

Heh, based on my incorrect and probably wrong experience Dutch and Swedes are the best non-native english speakers in term of both the accent and fluency.

Those and Icelandic people. But there's a fun correlation - see how much the US media content is played compared to local one per country. And which countries use subs rather than dubs or voiceovers in cinemas and TV. https://publications.europa.eu/resource/cellar/e4d5cbf4-a839...

If you have exposure to English media from young age and don't get a translation, you learn pretty quickly.