Disagree. This totally makes sense.
Yesterday people in America were buying TV's from people in China. Let's say the price of a given TV was $140.
Now that the CNY/CNH is 'lower' (in the sense that you now need more than 7 CNH to buy $1), the price of those TVs just fell.
Now maybe the price of the TV's at $140 was in some contract, but the next time the contract comes up for review, the lower CNY reflects the fact that someone in China will accept 'less' for their TV than they were yesterday.
Extend this logic from a 1% move to a 20%.
As prices fall, maybe people start buying more of their TVs from China than South Korea, cause relative to the price of TVs from SK, the Chinese TVs are now a 20% discount.
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Now, whether a falling FX makes for greater or lesser demand for Chinese financial assets, that's a different story. Would expect this to prompt capital flight.
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And finally, yes, currency does pay a dividend. Just usually in the form of a different interest rate. So for 'lending' to a developing currency (in the form of buying a financial instrument or holding a bank account), you generally earn the local interest rate.
When capital deems that country as more risky, then that is reflected in the yield of short term interest rates. Were you to lend to Brazil, you might want 1,2 or even 5% more than you get for lending to JP Morgan or the US Govt.
Now, the fact that this 'interest rate spread' doesn't really exist vis-a-vis China, well that's the whole issue at stake. If interest rates in China are too low, then you would expect people to want to exchange their CNY for USD, since why not put it in dollars if it doesn't cost you much. Again, hence capital controls to protect against capital flight.
Macro folks call it the 'trilemma' and we're seeing a real time experiment in it, on a massive scale, right here.
https://www.investopedia.com/terms/t/trilemma.asp