Bitcoin has really help the economy , this is just a nutshell of some notable works bitcoin has done to economy of many countries so i don't really see the reason why the government of some countries failed to make it a legal tender till now even after seeing what it has done to their economy.
The only country that Bitcoin has helped their economy are the country that have adopted Bitcoin to be used as the country currency but that isn't the only reason why Bitcoin has helped their economy because they still had to invest in Bitcoin too. The country that accepted Bitcoin had their reasons and the country that haven't invested too have their own reasons. Some country's government are afraid that Bitcoin is going to make them vulnerable to cyber attacks and other attacks by terrorist.
More country are going to be adopting Bitcoin soon as they begin to see that their currency isn't doing well because of inflation, as it keeps on losing value. Bitcoin can only help the economy if it gets used as an investment and not a currency because there's no benefit of Bitcoin to the economy when it gets used for buying and selling of commodity .