Low skilled workers doesn’t accurately describe what China brings to the table currently. They effectively are the only place in the world you can source certain parts of the electronic supply chain at the volume currently necessary. They’ve been up the technical ladder for decades at the same time as other places have shed that capability. It would take a long time for Vietnam to come online. I’d guess Korea or Japan would be closest and that would have dramatic price impact.
Nationwide ~1/5th of US imports come directly from China, that’s bumped a little when countries manufacture with Chinease parts but stays well under 1/4th of US imports and ~1/37th the US GDP.
Personally, I get very little directly or indirectly from China based on my shopping habits it’s mostly electronic gifts.
China does a lot of different thinks all the way up to building jet engines. However, the percentage of people employed at mod to high skill manufacturing is not enough to keep things going in the event of a trade war.