It is very relevant. This how one economy gets classified as service or industrial.
Even if we take different approach, overall industrial output of USA per capita, it still less than Germany's.
In just means that the US isn't a manufacturing economy. Manufacturing is a very small part of US economy but that doesn't mean that in absolute numbers it might be higher than other countries', especially if most of the goods manufactured were with high added value (e.g., the aforementioned jet engines).
