It's a nonsensical argument as you've discovered. It's due to the dollar value of things. And yes, jet engines are about as bespoke as you can get - incredibly man-hours intensive and it reflects in the price.

As some point folks will discover that dollars do not actually equal physical goods. Exporting 100 F35s at $100m/ea is not the same value to a country under duress as the capability to manufacture $10B of random consumer goods. Nevermind the supply chain of that F35 is not remotely contained to domestic manufacturing.

It's hand-wavy financialization of America speak.