I cannot really tell what your supposedly "simple solution" actually is. But it seems just a restatement of OPs, but filtered through a Brexiteer's compulsion to add a bit us-vs-them to the mix.

In that case it suffers from the same failures as OP: Starbucks would seize to exist because coffee still makes up 50%+ of their cost of doing business. And it adds an extra layer of "but why?" with an artificial distinction between domestic and foreign-produced goods.