Aside from the intellectual exercise of the question, why would it matter? Can you build a bike with only things sourced from your own city or your state, west of the Mississippi?

The bottom line is many things are more efficiently produced in other places. This has been the foundation of trade for centuries. I think it's great we can buy a product made less expensively somewhere else. This frees up our labor force to do things we are better positioned to do.

Of course, there may be specific industries were retaining domestic capabilities are necessary for national security, but bike tech certainly isn't in that category.