@blockchainttmft - I expanded a bit on my reply below and linked to the analysis posts by @ka82
https://steemit.com/bitcoin/@softgrip/the-future-of-crypto-and-fiat
It definitely is sustainable for the near future, but I'm just not sure if it will be BitConnect or something similar that is the final straw on the camels back that breaks fiat wealth.
Something will. We just don't 100% know what it is.