The users who are withdrawing Bitcoin profits to their respective bank accounts are already paying taxes to the government under Capital Gain tax mechanism if the income is more than the specified limit of country under taxation policies.Those who are evading taxes by not cashing out profits through banking system run away from taxes otherwise you have to pay tax even if it is not recognised as legal tender in any country.But if the government has put a complete ban on crypto usage then you don't need to file ITR for Bitcoin because you can't trade or invest in them as it becomes illegal in that prespective.But in other cases many are already paying taxes and government earning million dollars of revenue from crypto industry as well.