There are many factors of the global economy that determine the market-determined yield at a given time. The only way a country being "good with money" is in comparison to the yield of other central banks at the same time.

I don't have the data, but if Germany's yield followed a similar trend down then up, but remained below the US throughout, then the hypothesis holds.

For reference, German yield was around 1.5%, 0% and 0.25% on those dates (vs 3%, 1.5% and 3% for the US).

The elephant in the room in this kind of reasoning is Japan.

Japan shows that the narrative of "good country" vs. "bad country" and interest rates beyond the control of the Central Bank have little to do with reality.

Those interest rates don't move on their own. If the competition changes, those interest rates change too.

For example, if the share outlook for the next years looks unusually good/bad volatile/stable (compared to how it looked a couple of years earlier), then that makes shares more/less attractive to investors, and bond issuers have to adjust the rates they offer.

> Did the United States "get better with money" somehow in the last years before becoming "bad with money" again?

Yes, the economy started to boom but then the government went and issued massive corporate tax cuts while simultaneously increasing spending by quite a bit, which means increase in deficit.