The single most important parameter of digital currency is the stability of value. It should not fluctuates no more than 5% from previous day. Otherwise there will be a tremendous pressure to merchant accepting digital currencies as a payment who may loose the real value which is unacceptable.
At this time bitcoin, ethereum, and other digital currencies can not retain the value from speculative investor or traders. Rather they are enjoying the speculative results.
There are two fundamental problems with bitcoin/ethereum/etc that need to be corrected;
1. Value fluctuates by the speculative activities such that the price relative to fiat currencies changes more than 10% at times.
2. Transaction is not real time.
Maybe this is the way Satoshi Nakamoto wanted to avoid direct attack from the establishment if being considered as perfect alternative to fiat currencies, but I doubt it.
It is about time that they should look at the LondonCoin which has solutions to both.