I think that the French love of ideas is much older than the 20th century. I've got a feeling it has its roots in the Middle Ages with scholasticism and the founding of the Sorbonne. French culture is hardly the only culture that loves ideas. I would say that Jewish culture loves ideas even more as there's a strong tradition of studying and interpreting the Bible in depth.

What you said about how people dress is interesting. I actually quite like the American approach whereby you can just wear whatever you want. People in France are a bit more 'prescriptive' in how people should dress, which can be quite restricting. I actually quite like the fact that in the US, you can't tell if someone is a billionaire or not based on the way they dress. It means they see no need to dress up to show that they're rich. There's simply no urge to show off (for some, at least). Whereas in France, most rich people would dress up well to signal that they're wealthy. And while they may wear less brand-y, more understated clothing, it'll still cost a fortune.

You might be interested in Hofstede's cultural dimensions: https://www.hofstede-insights.com/country-comparison-tool?countries=brazil%2Cunited+states