> Again, offshoring normally implies that there are workers still in an "onshore" office.

Not workers doing the same jobs though. Look at how manufacturing was offshored over the past several decades -- for many companies, entire job trees within the US were eliminated. HQ is still in the US, but anything remotely having to do with manufacturing isn't. You have to go really high up the chain in those offshored manufacturing jobs before you see anyone actually interacting with an employee in the US.