I would add that there isn't an easy way to change crypto into fiat. When the time comes that I can send crypto to someone on the other side of the world, or across town, and they can receive that and easily change that to fiat, or vice versa crypto will boom.
I agree that if there is an easy and
fast way to buy (on-ramp) and to sell (off-ramp) on the cryptocurrency "super highway" that helps in at least these important ways:
1) it makes it safe for sellers to accept it because they know they can easily and quickly convert it into fiat currency
2) because the amount of time between when a buyer purchasing a cryptocurrency to spend it and when the seller converts this into fiat currency can be small
3) because this time can be small (a few seconds) the exposure to price volatility is also small
I emphasize "fast" because presently there isn't a fast way to do this. It can take over a week to buy a cryptocurrency such as bitcoin (e.g. CoinBase takes 10 days!). It takes several days to sell cryptocurrency.