It's not just that but also the mindset of entrepreneurship and growth versus stagnation and la dolce vita, which, while nice in the short term, is untenable in the long term.
Pieter Levels of NomadList fame talks about this often [0][1][2], he is Dutch, not American, so it's not like he's biased for America but he notes that it is disheartening for him to see Europe slip into mediocrity over time.
Ah I didn't see his latest reply, he normally lives in Asia, I thought he was still there. Regardless, he can live there and still want to improve his continent, as he mentions. Your comments remind me of this meme.
Europe has been mediocre for the entire modern times. France’s Haussmann marks the end of it with the Exposition Universelle of 1889 (Eiffer Tower) which really attracted people. Since then, we had to be rescued by Americans every time we went into war (even in Vietnam) and the art capital of the world is NYC. Maybe De Gaulle revived France a little (and he leveraged the UK/US help for that), but nowhere near what Shanghai or San Francisco did.
Europe is fine as a former success. Happiness has been high, life expectancy too.
Except it is now being ruled over by people who will neither bring it to the sky again, nor will keep the existing inhabitants.