How would different currencies effect capitalism?

Capitalism depends on two values that share a currency: money and capital. Money is liquid currency that freely flows through the economy. Capital is money that has been invested, in order to generate profit.

Under capitalism, people have private property. Private property enables the capitalist class to extract surplus value from the workers. The way they do this is under-compensating their workers. They pay them less in wages than the workers generate in value. The surplus is called profit.

But what if profit was in the form of a currency that was completely divorced from the currency that wages are paid?

Taiwan brings home Chinese factories, which may benefit China in the long run

Shifting some manufacturing jobs to Taiwan isn't an isolationist act - it's temporary management of a multi-national economic project. They aren't consolidating business into Taiwan, they're also spreading into Southeast Asia. And as soon as its politically viable to work in China again, they will.

The US has to "protect" Taiwan, and Hong Kong, but the reason there's so much anxiety in the West about them shows that China's gravity is too strong to overcome. Any type of internal economic growth of Taiwan can be utilized by China. And the fact that Taiwanese companies are more integrated into SE Asia doesn't change that, because China itself is even more integrated in SE Asia.