I don't think crypto currency has caused countries instability in economy. After all it is not crypto currency that is been used as major currency there. What ever they buy there will be in the countries currency and they pay with bitcoin so it is still there currencies that is been traded withCryptocurrency have caused some country economy instability cos the citizen do not spend the currency and do prefer to invest their cash in crypto, which reduces the income of the nation.
Crypto currency have made it possible for business worldwide to connect and make easy transaction with just little fees