The reason all component manufacture are in Asia is because labor costs make up a much larger percentage of the total cost for smaller lower margin components.
The final labor cost for a Dyson is much higher than just what they pay for assembly, you have to add all the wages for each part up the chain.
And that's a total BS claim. Apple is sitting on $100 billion now and still whining about how there are no companies in the US with sufficient manufacturing capabilities, as if that's forcing them against their will. In reality, there is nothing stopping them from creating such factories in the US or elsewhere. However, they can't get 10,000 workers in employee housing and, at the snap of their fingers, put them all on the assembly line in back-to-back 16 hour shifts. Ultimately, it's not about production facilities nor simple labor costs, but rather how they can treat Chinese workers.