"Do you think that existing financial system can be replaced with blockchain controlled systems independent from governments?"@adsactly -
Yes, they could. But presently the governments control the access to the crypto exchanges through their control of the internet. And governments aren't going to relinguish their control and power without a fight.
So the real question in my mind is "How can the crypto exchanges become independent from governments."
Note: This doesn't mean not paying taxes on earnings because I believe that people should pay their appropriate taxes which are set by each government.