Europe has either been expanding to include, if you look at EU, or it has always included, if you take the geographical boundary, a lot of very poor southern and eastern European countries.

I think EU expansion is a good thing but it makes even well intentioned comparisons difficult if e.g. Germany re-absorbs East Germany, or other nations join the EU

Poland was about 20% of the USA by PPP in the 90s, 40% when it joined the EU and 60% now.

Is that a success or a failure? It can definitely make some stats look worse.