I doubt this would do any good for them.
* Their currency would be totally exposed to 3rd parties.
* They would loose the control over the rates, which are an important tool to attract investments, if are stable and controlled well.
* AFAIK some Chinese private companies control large part of the mining network. Basically the central bank would be in private, and foreign hands.
* The slow transactions would make it totally infeasable for use in everyday life, especially as people there have limited access to necessary technologies (stable network connections all round the countries, stable electric power everywhere), so daily transactions of the ordinary people would either fall back to barters, or use some fiat paper money, eg. USDs.
I totally don't get how could you reach tis conclusion, your whole post is a SV bubble wishful thinking with some trendy bullshit, eg. software eating the FED, fed is replaced by code. Bitcoin does better than centralbanks. If some currency looses 30% of its value a single day, that is not a sign of health, and this happended the very week with bitcoin. Actually Bitcoin does its job worse than an african dictatorship's currency, if its job is being a fiat currency, which is useful for the people in daily life.
I doubt its job is that, so it may do its job well, but for this task it is unsuitable.