It's not finite. The supply of cryptocurrencies is effectively infinite. There's almost no barrier to entry. In the closest historical equivalent, the wildcat banking era, at least you had to have state-chartered bank. [1] But what's it take to launch a cryptocurrency these days? Is it anything beyond a tech guy, a marketing guy, and a a credit card with a little room?

[1] https://en.wikipedia.org/wiki/Wildcat_banking