Digital currency can never create any wealth, it can only absorb wealth, due to the very high cost of the supporting infrastructure. As and when the investment in such digital currencies is cashed in, the total sum recovered will always be significantly less than the total sum originally invested. Wealth, per se, will very definitely be destroyed.
Money, per se, is of no tangible use to anyone. It only becomes useful once it has been spent on purchasing goods or services. There might well be a time when an increasing number of digital currency investors need to cash in their investments to spend on something useful. This will cause their price to fall, which in turn will cause an escalation in the sale of these investments, triggering an exponentially increasing downwards spiral. At the end of the day, a lot of these digital currency gamblers will lose everything.
Investing in digital currency is gambling.