That was plenty of reasons to take the country seriously! Also, the US has been the most powerful cultural exporter for a very long time. It’s still the case, whenever anything becomes huge in the US we get our local version in each European countries. Our far right parties are parroting American right politics, even copying the terminology as is
It's not all US, but as you said things start in the US and trickles down across the rest of the world, so that's also true for its decadence.
Lets start with movies: Most top grossing movies are still American based and centric. I was reminded of this recently when Obsession came out and I tried to get my German friends to watch it. They missed so many subtle 'Americanisms' in the movie that it really gave me a new perspective on how ingrained the culture is. 10 years ago living in Europe I was amazed at how much American music French people listen to and sing to. Even on random French shops its nothing but American music playing. I don't believe they suddenly switched to French music. (Is there some pop artist in France stealing the charts right now? Im curious to learn). And this is the country with Académie Française.
The Chinese are trying: Ne Zha 2 was quite nicely animated and it grossed an impressive amount but that seemed more like a one trick pony given that it really attracted massive Chinese audiences and they seem to know how important the film was. This is just an opinion but it was not a memorable film like I'd expect from a Disney classic.
Then there is food: Its fascinating how Luckin had its massive comeback and has forced Starbucks to retreat in China and other markets. Mixue might do something similar to chains like DQ and Baksin Robbins, (lets see what happens). I have yet to see the Chinese Mcdonalds but maybe its in the shadows waiting for the right moment like a lot of Chinese companies.
In terms of Gaming, it still seems like despite all the BS, the market is still treating Western game publishers as the gold standard (and mainly American ones at that). The market dynamics are different for Gaming vs others because gaming is so diverse. Maybe there isnt really a leader given the ease of competition. Same goes for music. Streaming seems like what the market wanted or else they would have stuck with physical media.
Enshittification is culture too, and it's certainly spreading.