The Swiss?
Norway?
And I was in Serbia lately, and while it was not as developed as NW-EU, nobody there described it as decaying (and many said they experiences decay when living in western nations over the past 2 decades).
Denmark is not just decayed, it is completely rotten.
I don't know about the truthness of this claim, but you are definitely getting the upvote for the humour.
The only country in Europe that is the exception is Norway which is not part of the EU.
With OP postulating that it is to enable corruption, and a sub-reply affirming that it is therefore the trait of a country in decay, bringing in Serbia as a counter-example is hilarious.
Serbia ranks 116th in the corruption perception index, Germany 10th. (Lower is better)
Yeah, a lot of the western countries that aren't wealthy enough to afford the luxury of indulging in absurd farcical politics and policies over the past 40yr are doing pretty decent.