> It strikes me as extremely odd that it's become so normalized that the U.S.'s role in trade is simply as a buyer of goods.
It should strike you as odd, what you're saying is wrong.
The US exports $2.5 trillion worth of goods and services, including $1.7 trillion of goods.
The US is the world's #2 exporter of goods. With services included, the US is nearly the world's #1 exporter. In 2018, the US was behind China by only about $80 billion in total exports. That's nearly three times the #4 export country, Japan.