It's rooted in societal culture and what people incentivize (ie assign the highest multiple to).
Until Americans take on a mindset of longterm/family (as I've seen many Chinese families express), they'll be doomed to make short term decisions. Right now very few Americans are able to accept an optimization that looks like "I invest today, and my grandkids will get the returns". So America is stuck in that local maxima of invest for next few quarters. The obvious tradeoff being the risks/ability to predict the future.
I want my investments to pay back over 30 years to me. I don't care about quarter to quarter returns. I don't need to invest for my grandkids for any of this.
As I understand the gross summarization of Chinese culture is that they're extremely family oriented. Anecdotally I've heard of grandmas acting like their homeless to earn a little money to give to a grandson which drives a Ferrari. They do it because they love and maximize for the next generation.
Plenty of money is being made by taking the short term route. Execs move factories to China and Mexico and they'll get a fat bonus while the workers will see their communities go into decline, and the government starts erecting trade barriers to protect what's left.
At some point in my lifetime, the mindset switched from "I'm investing because I want to see long-term, steady growth and get regular dividends" to "I want to make as much money as possible as quickly as possible and damn the consequences to others".
The short-sightedness and greed is destroying so much.
Until Americans take on a mindset of longterm/family (as I've seen many Chinese families express), they'll be doomed to make short term decisions. Right now very few Americans are able to accept an optimization that looks like "I invest today, and my grandkids will get the returns". So America is stuck in that local maxima of invest for next few quarters. The obvious tradeoff being the risks/ability to predict the future.