[inglor_cz]

True, but we do not have anything resembling WWII-levels of destruction on the vast majority of the continent, so the effort needed to get back on track is an order of magnitude lower. In 1945, Mariupols were everywhere.

And post-WWII Europe was forcibly split into competing power blocks, which strangulated a lot of the pre-WWII commerce. Contemporary EU is a common market where goods and workforce can freely flow. This compensates for the lack of young people somewhat.

For example, Germany post-WWII was seriously handicapped by the fact that they lost a large portion of their male population in war, either killed/maimed, or taken prisoner by the USSR which only let them return after 1950.