Prussia has always been much more than any undistinguished local kingdom in terms of revenues, self-government, stability, culture
Dude, Royal Prussia was a province of Poland, Ducal Prussia were as vasal of the Crown with those revenues and whatnot you mentioned above. It was a backwater with only one mayor city and a port - Konigsberg. Look, you don't know so shut up and stop showing off.
The first Protestant semi-state due to the grace of his Royal majesty the King of Poland, the Grand Duke of Lithuania, Duke of Ruthenia,
Prussia, Mazovia, Samogitia, Kiev, Wolynia, Podolia, Podlasia, Smolensk .......
Maybe a little, but in practical terms I think it's mostly irrelevant.
Sure thing. Never claimed otherwise. I and BB going a long time on PF and we have our debates all the time. In practical terms is irrelevant.
For many of those years, Danzig was mostly German in culture
As were many cities in the Kingdom of Poland, yes elites of Gdansk were mostly German in culture or that culture dominated in those prominent circles. Yet the dominant culture in the province was Polish like elites and their culture were Polish.
--- Gdansk became that prosperous due the fact it has been the mayor port for the Polish trade they at time fed half of Europe.