it is true, that in fact it returns to the policy of the state authority. I think every particular exchange pays taxes on the government, and that is a good thing for the country's economy. as for countries that prohibit the use of bitcoin due to misuse that does not follow the policies and regulations of that country. Every platform that operates under the auspices of the state government in the economic sector provides rules to allow the exchange legally, if there is an input or annual tax payment to the state.