Economics enters into it.

Like salmon caught in Alaska, flash frozen, then shipped to China where they are cleaned and filleted, packaged, and shipped to the US for retail sale. China doing their part cheaper and maybe because they don't have the labor to do the quantity in Alaska or elsewhere.

Lots of things get shipped around like this, with components made in A, B, and C, shipped to X for assembly, then to Z for packaging or whatever, and then to 1-2-etc. to be sold.

Larry