The explicit definition of an asset is something that has 'explicit' value expressed by obtaining real world assets that can be priced to a discrete number minus the effort involved to obtain and hold the original asset prior to exchange. If the total sum is less than positive or that the expense and effort costs more than the exchange value then no tax or governmental control should ever be required or enforced in such situations because the overall effect is confiscatory control over items that have not increased in value in comparison to the inputs to gain such assets.
There are a lot of people simply acquiring cryptocurrencies because the fiat money they hold now is losing value so fast that buying crypto coin is much more appealing than keeping assets that lose value faster with inflation. Another reason to hold internet coin is that there isn't banking fees and regulations and holding periods when you deposit and remove money for whatever you want.