Would they need BTC? With 1.3 billion potential users wouldn't that be enough?
Having their own crypto coin for improving their economy is a pretty smart move . But the support will only be shown by natives .
Obviously China's population will somehow strengthen their local coin ( even though a lot of population includes elderly ) . But the support that is with bitcoin cannot be shaken by any other local coin . The main proof is the rise of bitcoin even after the China ban . But if every country starts making their own crypto coins then that might be a reason of big concern for sure.
I think its not about that anyone can make crypto because its not easy job to make crypto and then keep maintain its high price bitcoin is actually decentralized and its not going to easy to defeat bitcoin is going to do hard work in market and it keep its price maintain with high price and bitcoin is such a challenger currency in market.