There is a big competition is going on between local currency and cryptocurrecies. If crypto enters in to the market surely it will disappear the local currency. Because the benefits is large when compared to local currency. So people automatically use cryptocurrency only. In future surely bitcoin will rule the crypto market.
Man, I do not see any competition between the cryptocurrencies and fiat. Local money will always exist as each country has many old people that will never understand crypto. Nothing to be afraid of.