I would say more than it is a beginning of success that has not yet materialized in total success. Indeed,  the objective of Bitcoin was initially to replace existing currencies,  controlled by central authorities, with a non-centralized virtual  currency whose value is determined by its users. This  very ambitious vision has rallied millions of people who have invested  heavily in Bitcoin to exceed a capitalization of 100 billion dollars in a  few years. Even  if this seems impressive, we are still far from seeing bitcoin or other  crypto-currencies, replacing the classic currencies, and this for the  following reasons:

1- The technological limitation: Bitcoin currently has a capacity of 3 to 4 transactions per second. Even  if other crypto-currencies have a much higher capacity than Bitcoin  (example: 20 capacities per second for the ethereum), we see that  cryptocurrencies have a capacity far behind the current payment  technologies like Visa which has a capacity of 1667 transactions per second. This seriously limits the massive adoption of crypto-currencies. Nevertheless,  with the technological improvements made to cryptocurrencies, one could  see a considerable increase in their capacity in the years to come.

2- Transaction costs: with the increase in Bitcoin mining costs, Bitcoin transfer fees have increased exponentially. Pay for everyday things like shopping, small purchases etc. is no longer interesting for people with Bitcoin.

3-  Fluctuations: The value of Bitcoin fluctuates very rapidly and does not  yet provide stability allowing merchants to accept payments in Bitcoin.  As long as the value of Bitcoin is not stable, it can only be adopted by investors or merchants who can tolerate high risks.

Bitcoin  or crypto-currencies in general have marked the beginning of a new  revolution in current monetary systems, but they still have a long way  to go before they succeed in realizing the initial vision of replacing  centralized money with a decentralized currency. .