Cryptocurrencies won't contribute to the reconstruction, rather they will further degrade the global economy. Why?
If we substitute the concept of state's money to people's money, government or banks will no longer be the biggest player in economic construction as cryptocurrencies are already distributed among group of people.
The current holders will become new ultra-rich and non-holders will become poor. As a result, economy will crack drastically.
Man this is a speculation even bigger than the speculation among the crypto markets!
First crypto currencies will never replace fiat, so the rich (banks) are not really threaten by crypto. This will only force them to adjust their fees and taxes, because a decent alternative to payments and investments is emerging and they have to adapt. Also don't forget that the marketcap of all crypto, and not just bitcoin is at 300B, and the marketcap of fiat is on the trillion figure, so no, the rich are not getting poor. Also if bitcoin was going to replace the fiat system, and that is something that will never happen of course, the rich could still by more bitcoin than anyone else, so they would still be richer.
Nothing is about to change on that perspective. A new asset was born, and that only made those who first got into it richer, and nothing else. That is perfectly normal, and every time someone creates something new and innovative that gets very popular, that person will get richer.
Steve Jobs got rich, Bill Gates got rich, Mark Zuckerberg got rich, everyone involved in google got rich, and so on.
Economy will not crack because of bitcoin.