But this achievement is less even impressive than a "OK, we've done the US, now let's look at other countries"

The problem is that the US can export it's carbon-intensive industries and even consume new carbon intensive entities produced by other countries. For example, US investors certainly consume a modest fraction of bitcoins mined in China and bitcoins wind-up consuming not just a lot of energy but also form a new source sort of carbon-intensive production.

Solar and wind power are becoming competitive with oil in general but this can never by itself halt hydrocarbon-energy production 'cause as it's relative price drops, there's always a practical use for hydrocarbon-energy close to the source, where pumping it out of the ground is nearly free.