Bitcoin is exciting because it shows how cheap it can be. Bitcoin is better than currency in that you don’t have to be physically in the same place and, of course, for large transactions, currency can get pretty inconvenient.
It is not a speculative investment even though it is being used as such by other people. As Bitcoin network grows the value of Bitcoin grows. As people move into Bitcoin for payments and receipts they stop using US Dollars, Euros and Chinese Yuan which in the long-term devalues these currencies.
The same people who thought Bitcoin at $100 was expensive, now think it is fairly valued at $54,000.