If the US knew it was losing and it was over for them, the US be for scorched earth. They would take everyone down with them. That's what the Chinese don't understand how Americans think. So thinking the US thinks more about the well-being of the world as a whole doesn't calculate in their thinking so appealing to Americans' sense of humanity doesn't work. Just look at what's happening now. The US is okay with sacrificing it's allies' well-being for what the US wants. That's what US allies are complaining about.
What China should be doing instead is talking about how much Americans are personally going to lose. As Mao said, "One death is a great tragedy. Ten thousand deaths is only a statistic." What made Americans turn against the Iraq War? It was when the American media was no longer lionizing every KIA the US suffered and the only people left to morn were only the family. This is when Americans say to themselves, "Why did these Americans have to die?"
You want to look at it at a smaller scale? Just look at how the West is changing their language from decoupling from China to de-risking. You think they did that because they saw how it would hurt everyone since China is the world's economic engine? No they did it because they suddenly realized how much they were going to lose if China decoupled with them. Like I said before in this forum, they can stop selling advanced technology to China. What is their definition of "advanced technology"? It's as simple as they have it and no one else does. It means also what they still expect to sell to China are the things that China can get somewhere else meaning the West makes zero-money from the largest and still growing market in the world. They're going to lose big time.