The global economy is nearly 80 trillion USD per year. Payments using any type of cryptocurrency as a medium of payment is a tiny fraction of this total.
What are some of the reasons preventing cryptocurrency from being more successful as a medium of payment?
Crypto currency is a completely new kind of digital money. Do not expect that in a few years all people will switch to using crypto currency. This process will be very lengthy and will take many decades. Individuals and now make payments in the crypto currency, but so far this is not often the case. Everything has its time.