> And what happens if China decides that it is no longer in their interest to allow Americans access to cheap aluminum extrusions, hotends, motors, and controllers?

We make our own. You seem to be under the common delusion that because only a tiny % of people work in manufacturing compare to 70 years ago, that mean the US doesn't to manufacturing. In fact the US is manufacturing more than ever with just that tiny % of people. Be glad you don't have to work a boring assembly line job.