You can use an ATM (or localbitcoins) to cash out Bitcoin without any connection to your bank account. Bitcoin doesn't have to be ubiquitous to use it even today, you just have to find businesses that accept Bitcoin. A buddy of mine accepts rent from a tenant in Bitcoin. There are exchanges to buy gift cards or Amazon credits with Bitcoin which you can use in real life to buy food. You can realistically go about your life completely in 2019 with just magic internet money. What a time to be alive.
Maybe you’ve never heard of Fold app or Bitrefill. Some of us are actually trying to build a circular bitcoin economy. These companies not only offer onramps and offramps to the ecosystem, but they actively fund and incentivize building. Yes, they make a profit too.
I'm sure other forms of exchange, for example, USD to GC, can still be used to launder money. This is not exclusive to cryptocurrency as you would imply.
