Bond prices shooting up is a result of market losing trust in US, or it's ability to not default.
Dollar is famous backed by $700T military. But the world has seen how it failed to secure a strait.
The current US government has broken all kind of promises. I want to highlight two in particular - free trade and immigration.
World economy has benefited for decades on the promises of free trade. The tariffs have eroded the promise and trust.
The government is also openly supporting elements who are hostile to immigrants. Immigrants are the backbone of US economy, has been for over hundred years. Immigrating to the US requires years of preparation, long term planning, and giving up on other luxuries and opportunities. When the government starts breaking promises by changing rules and moving the goalposts overnight, it discourages participation.