* Mining has become highly centralized, the opposite of its original intent.
* Transaction fees are too high to justify its use in every day transactions and small transfers.
* Very few merchants accept it for every day transactions, and the number has decreased over time.
As an idea, a hope, the starting point for iterating on the future of money.
As a way to make the society think and debate.
And as all that, I think it had been successful.