Cryptocurrency is not able to replace real money. In relation to them, it will always be an auxiliary means of payment, since states will always protect the circulation of their national money. Cryptocurrency, at the same time, can and should successfully go along with the usual currency, and there may be various options and combinations of such walking.
I agree.
Furter, I guess, given the superiority of the blockchain technology, Govs will put their currency on the blockchain, so there will be a crypto$, a crypto€, a cryptoyuan etc.
Can we call blockchainised legal tenders "cryptocurrencies"?
Regulated cryptos will live along with national official currencies (legal tenders), sometimes supporting them, sometimes in competition with them.
Non-regulated cryptos or exchanges will play a marginal role.