This is entirely untrue. Almost anywhere you live in the U.S. you can find local brands with local production.

Where can I find an oven made with entirely US parts (or even ~85-90%+)?

I'll tell you in advance that I haven't been able to locate one in a few years of looking. Most major appliances are, at best, 60-80% american with no accurate accounting, even if they're "assembled in the USA". Cars are the only thing with accurate sourcing labels due to legislation.

Entirely US parts is a very high bar. Isn't it the final product design and assembly that counts in the end? If China has a comparative advantage making resistors, who cares, let them.

And the local production is an assembly of something really made in china.